geometry

list triangle congruence theorems/postulates

SAS, SSS, ASA, AAS, HL

biconditional?

conditional statement with "if and only if"; only if both conditional and converse are true

law of syllogism?

if p -> q and q -> r are true statements, then p -> r is a true statement

law of detachment?

if a conditional is true and its hypothesis is true, then the conclusion is true

if a transversal intersects two parallel lines, then alternate interior angles are

congruent

if a transversal intersects two parallel lines, then same side interior angles are

supplementary

if a transversal intersects two parallel lines, then same side exterior angles are

supplementary

if a transversal intersects two parallel lines, then corresponding angles are

congruent

if a transversal intersects two parallel lines, then alternate exterior angles are

congruent

if two lines and a transversal form corresponding angles that are congruent, then the two lines are

parallel

if two lines and a transversal form alternate interior angles that are congruent, then the two lines are

parallel

f two lines and a transversal form same side interior angles that are supplementary, then the two lines are

parallel

if two liens and a transversal form alternate exterior angles that are congrent, ten the two lines are

parallel

if two lines and a transversal form same side exterior angles that are supplementary, then the two lines are

parallel

if two lines and a transversal form same side exterior angles that are ______, then the two lines are parallel

supplementary

if two lines are parallel to the same line, then

they are parallel to each other

if two lines are perpendicular to the same line, then

they are parallel to each other

the sum of the measures of the angles of a triangle is

180

list classifications of a triangle by angle

equiangular, acute, right, obtuse

list classifications of a tirangle by side

equilateral, isosceles, scalene

what is an isosceles triangle?

at least two sides congruent

what is a scalene triangle?

no sides congruent

exterior angle of a polygon?

angle formed by a side and an extension of the adjacent side

the measure of an exterior angle of a polygon is the sum of what two angles?

the two remote interior angles corresponding to the exterior angle

convex polygon?

polygon with no diagonal with points otuside the polygon

concave polygon?

has at least one diagonal with points outside the polygon

sum of measures of angles of ngon?

(n-2)180

the sum of the measures of the exterior angles of a polygon, one at each vertex, is

360

slope intercept form?

y = mx + b

point slope form?

y-y1 = m(x-x1)

standard form of a linear equation?

ax + by - c

slopes of parallel lines are

equal

perpendicular lines have a slope product of

-1

if two angles of one triangle are congruent to two angles of another triangle , then

the third angles are congruent

describe SAS postulate

if two sides and included angle are congruent....triangle is congruent

describe ASA postulate

if two angles and included side are congruent....congruent triangles

describe AAS theorem

f two angles and a NONINCLUDED side .....congruent

isosceles triangle theorem?

if two sides of a triangle are congruent, then the angles opposite those sides are congruent

triangle midsegment theorem?

if a segment joins the midpoints of two sides of a triangle, then the segment is parallel to the third side, and is half its length

if a segment joins the midpoints of two sides of a triangle, then the segment is _______ to the third side, and is ______ its length

parallel, half

if a pt is on the perpendicular bisector of a segment, then

it is equidistant from the endpoints of the segment

if a point is equidistant from the endpoitns of a segment,

it is on the perpendicular bisector of a segment

If a pt is on the bisector of the angle, then

that point is equidistant from the sides of the angle.

if a point is equidistant from the sides of the angle, then

the point is on the bisector of the angle.

distance from point to line?

perpendicular distance from point to line

concurrent lines?

three or more lines that intersect in the same point

state the converse of this statement: if it rains, then they will cancel school

if they cancel school, it will rain

state inverse of this statement: if it rains, then they will cancel school

if it does not rain, they will not cancel school

state the contrapositive of this statement: if it rains, then they will cancel school

if they do not cancel school, it is not raining

the statement and the ______ have the same truth value

contrapositive

the converse and the ______ have the same truth value

inverse

what are concurrent lines?

3 or more lines intersecting in one point

what is the point at which concurrent lines intersect?

point of concurrency

the perpendicular bisectors of the sides of a triangle intersect at a point of concurrency equidistant from the ______

the perpendicular bisectors of the sides of a triangle intersect at a point of concurrency equidistant from the vertices

the ______- of the _____ of a triangle intersect at a point of concurrency equidistant from the vertices

perpendicular bisectors, sides

the _______ of a triangle are concurrent at a point equidistant from the ______

angle bisectors, sides

circumcenter of a triangle?

point of concurrency of the perpendicular bisectors of a triangle

what it is called when a triangle is inside a circle?

circle is circumscribed about the triangle

Find the center of the circle that you can circumscribe aobut the triangle with vertices (0,0), (-8,0), and (0,6)

-4,3

find the center of the circle that you can circumscribe about a triangle with vertices (0,0), (-4,0), (0,-6)

-2,-3

point of concurrency of the angle bisectors of a triangle?

incenter of the triangle

what is it called when a circle is inside a triangle?

circle inscribed in a triangle

what is the median of a triangle?

segment whose endpoints are a vertex and the midpoint of the opposite side

the medians of a triangle are concurrent at a point ____ the distance from each _____ to the ____ of the opposite side

2/3; vertex; midpoint

what is the centroid?

the point of concurrency of the medians in a triangle

what is the difference between a median and a perpendicular bisector?

a median does not necessarily bisect the segment at a right angle, also it has an endpoint at a vertex

go to the following link: http://image.absoluteastronomy.com/images/encyclopediaimages/t/tr/triangle.centroid.median.png. O is the centroid of ABC. AE = 12, find OE.

4

go to the following link: http://image.absoluteastronomy.com/images/encyclopediaimages/t/tr/triangle.centroid.median.png. O is the centroid of ABC. OE = 6, find DE.

(1/3DE = 6; DE = 18) 18

what is an altitude of a triangle?

the perpendicular segment from a vertex to the line containing the opposite side (see link: http://www.geogebra.org/en/wiki/images/e/ea/TriangleAltitudePicture.jpg)

go to the link: http://www.icoachmath.com/Sitemap/images/Altitude%20of%20a%20Triangle2.jpg which of the images is an altitude?

figure 3

in an acute triangle, where is the altitude?

inside the triangle

in a right triangle, where is the altitude?

a side

in an obtuse triangle, where is the altitude?

outside the triangle

t/f: altitudes can lie outside the triangle

T

what is the orthocenter of a triangle?

point at which altitudes intersect

go to textbook page (lib) 260, #15. what is AB?

altitude

t/f: if a segment is perpendicular to another segment in a triangle, then it must be the bisector.

F

what is the inverse of the following statement? If a triangle is isosceles, it has two equal sides.

if a triangle is not isosceles, it does not have two equal sides.

T/F a conditional statement and its inverse always have the same truth value.

F

T/F: the inverse of a biconditonal is always true.

T

What is the negation of the following statement: If an angle is a straight angle, its measure is 180.

an angle is not a straight angle.

if a condition's symbolic form is p -> q, what is the symbolic form for the negation?

~p

what is an indirect proof?

proof where statement and its negation are only possibilities; and negation is proved wrong

if a = b + c and c > 0, then?

a > b

The measure of an exterior angle of a triangle is ______ than the measure of each of its remote interior angles

greater

if two sides of a triangle are not congruent, then the larger angles lies opposite

the longer side

consider this triangle: http://2000clicks.com/mathhelp/TriangleABC.gif none of the sides are congruent. which is the largest angle?

B

list the angles in this triangle (http://2000clicks.com/mathhelp/TriangleABC.gif) in order from smallest to largest

B, A, C

if two angles of a triangle are not congruent, then teh longer side lies oppose the

larger angle

in general, what can be said about the relationshiup between the size of an angle and the length of the opposite side?

the bigger the angle, the bigger the side

What is the triangle inequality theorem?

the sum of the lengths of any two sides of a triangle is greater than the length of the third side

the sum of the lengths of any two sides of a triangle is _____ ythan the length of third side

greater

can a triangle have side with the given lengths? 5, 12, 10

yes

can a triangle have sides with the given lengths? 2,4,7

no

write (a) the inverse and (b) the contrapositive of the statement.if a polygon has eight sides, then it is not an octagon.

(a) if a polygon does not have eight sides, then it is not an octagon. (b) if a polygon is not an an octagon, then it does not have eight sides.

what is the converse of a conditional?

switch of hypothesis and conclusion

describe the relatioship between a midsegment and the third side of the triangle?

parllel, and half itse length

identify the two statements that contradict each other: I. pqr is a right triangle II. pqr is an obtuse triangle III. pqr is scalene

I and II

parallelogram

quad with both pairs of opposite sides parallel

rhombus

parallelogram with four congruent sides

rectangle

parallelogram with four right angles

square

parallelogram with four congruent sides and four right angles

kite

quad with two pairs of adjacent sides congruent and no opposite sides congruent

trapezoid

quad with exactly one pair of parallel sides

quadrilateral

polygon with four sides

isosceles trapezoid

trapezoid whose nonparallel opposite sides are congruent

t/f: a square is a rhombus

T

how many pairs of adjacent sides congruent does a kite have?

2

how many pairs of opposite sides congruent does a kite have?

0

t/f: a trapezoid can have two pairs of parallel sides

f

what is the differences between an isosceles trapezoid and a regular trapezoid?

the nonparallel opposite sides of the issosceles trapezoid are congruent

how many pairs of parallel sides does a kite have?

0

a square can be considered the intersection of what two shapes?

rectangle, rhombus

Two sides of a rhombus are 3b + 2 and 4b - 2. Find b.

4

opposite sides of a paralleogram are

congruent

what are consecutive angles?

angles of a polygon that share a side (i.e. same side interior angles in a parallelogram)

in this parallelogram (http://kathrynportfolio.us/jpgs/parallelogram2.jpg), consider that angle A = 112. What is angle D? B? C?

68, 112, 68

opposite angles of a parallelogram are

congruent

In this paralel.ogram (http://kathrynportfolio.us/jpgs/parallelogram2.jpg) consider that DC is 3x - 15 and AB is 2x + 3. What is x?

18

The diagonals of a parallelogram have what relationship to each other?

bisect each other

if three or more parallel lines cut off congruent segments on one trasversal, then

they cut off congruent segments on every transversal

name four methods of proving that a quadrilateral is a parallelogram

1) diagonals bisect each other2) one pair of opposite sides is both congruent and parallel3) both pairs of opposite sides are congruent4) if both pairs of opposite angles are congruent

relationship between diagonal and angles of rhombus?

each diagonal bisects two angles

the diagonals of a rhombus are ____ to each other

perpendicular

the diagonals of a rectangle are

congruent

if one diagonal of a parllelogram bisects two angles of the parallelogram, then it is a

rhombus

if the diagonals of a paralloalgram are perpendicular, then

it is a rhombus

if the diagonals of a parallelogram are congruent, then the parallelogra m is a

rectangle

list ways to determine if pgram is rhombus:

1) each diagonal bisects two angles 2) diagonals are perpendicular

list ways to determine if pgram is rectangle:

1) diagonals are congruent

t/f: diagonals of all parallelograms are congruent

FALSE

t/f: diagonals of parallelograms are perpendicular

F

the base angles of an isosceles trapezoid are

congruent

the diagonals of an issosceles trapezoid are

congruent

list four characteriztics of isosceles trapzeoids

1) legs congruent 2) bases parallel 3) base angles congruent 4) diagonals congruent

diagonals of a kite are

perpendicular

list characteristics of a kite

1) twopairs of adjacent sides congruent 2) no opposite sides congruent 3) perpendicular diagonals

a/b = c/d is equivalent to

1) ad = bc 2) b/a = d/c 3) a/c = b/d 4) (a+b)/b = (c+d)/d

list four other expressions that x/y = 5/6 is equivalent to

1) 6x = 5y 2) y/x = 6/5 3) x/5 = y/6 4) (x+y)/y = 11/6

golden rectangle definition

rectangle that can be divided into a square and a rectangle that is similar to the original rectangle

definition of similar?

1) corresponding angles are congruent 2) corresponding sides are proportional

t/f: figures fcan be congruent if angles are proportional

F

approximate golden ratiom

0.470844907

list similarity postulates/theorems for triangles

AA~, SAS~, SSS~,

what is the AA~ postulate?

if two angles of one triangle are congruent to two angles of another triangle, then they are similar

what is hthe SAS~ theorem?

if an angle across two triangles is congruent, and the surrounding two sides are proportional, the two triangles are similar

what is SSS~ theorem?

if corresponding sides of two triangles are proportional , then the triangles are similar

the altitude to the hypotenuse of a right triangle divides the triangle into two tirnagles. describe these.

they are similar to the original triangle and to each other

what is the geometry mean of 6 and 4?

2sqrt(6)

the length of the altitude to the hyp of a right triangle is the ______ of the lengths of the segments of the hyp

geometric mean

the altitude to the hyp of a right triangle separates the hyp so that the length of each leg of the triangle is the geometric of what two lengths?

the length of adjacent hyp segment and the length of the hyp itself

go to textbook page 441, example 2. solve for x and y.

y = 2sqrt(5); x = 6

go to textbook page 441, example 2 CU. solve for x and y.

y = 4sqrt(3); x = 8

go to tb p 441, example 3. how far is Marla from the info center? (what is AD)?

AD = 180 m

go to tb p 441, example 3 CU. answer the q.

240 m

p. 442, #15.

9

p. 442,#17.

10

p. 442, # 19.

12

What are the two requirements for the Side Splitter Theorem (i.e. dividing sides of traingle proportinally)?

1) line is parallel to one side of a triangle 2) intersects other two sides

If three paralle lines intersect two transversals, then the segments intercepted on the transversals are

PROPORTIONAL

p. 447, CU 1; show work

(x+1.5)/x = 2; x + 1.5 = 2x; 1.5 = x

if a ray bisects an angle of a triangle, then it divides the opposite side into two segments that are _________ to the other two sides of the triangle.

proportional

p. 448, CU 3. solve for y, show work.

3.6/y = 5/8. 5y = 28.8. y = 5.76

if the similarity ratio of two similar figures is a/b, then

1) the ratio of their perimeters if a/b and 2) the ratio of their areas is a^2/b^2

p. 456, example 3. solve.

6.25 * 13 = ~81 bushels

p. 456, CU 3. solve.

$6.95

p. 456 #1.

1/2, 1/4.

p. 457, #9.

216/108 = x/192; $384.

what is the tangent ratio?

opposite/adjacent

cosine ratio?

adjacent/hypotenuse

sine ratio?

opposite/hypotenuse

what is the relationship between the sine and cosine of an angle?

sin x = cos (90-x)

what is a vector?

any quantity with magnitude and direction

what is the sum of vtwo vectors with coordinates (6, 5) + (7, 2)

(13, 7)

what is pythag equation of obtuse triangle?

c^2 > a^2 + b^2

what is pythag equatin of acute triangle?

c^2 < a^2 + b^2

what are leg lengths of of 45 45 90 triangle with hyp = sqrt(2)

1, 1

what are leg lengths of 30 60 90 triangle with hyp = 1

1/2, sqrt(3)/2

area of a trapezoid?

1/2h(b1+b2)

area of rhombus or kite?

1/2d1d2

area of rhombus/?

1/2 d1 * d2

area of kite?

1/2 d1 * d2

what is apothem?

perpendicular distance from center to a side

what is the area of a regular polygon (using apothem?)

1/2ap

what are adjacent arcs?

arcs of same circle that have exactly one point in common

what is the circumference of a circle?

c = 2pir

what is the area of a circle?

pir^2

what is the formula for arc length?

measure of arc/360 * circumference

Find arc length of an arc with degree 100 and a circle with radius 15.

8.3pi

what is the area of a sector of the circle?

measure of arc/360 * area of circle

what is the area of a sector of circle with degree 60, and with a circle with radius 5.

25/6pi

geometric probability?

where points represent outcomes

elena's bus runs every 25 min. if she arrives at her bus stop at arandom time, what is the probability that she will have to wait at least 10 minutes for the bus?

05-Mar

find the area of a regular pentagon with 8 cm sides.

110.11

what is the area of a tirangle given SAS?

one half product of lengths of two sides and sine of included angles

find the mangitude and direction of the vector on p. 494 #15.

21.8 degrees north of east, mangitude 53.85

is the resultant the sum of the initial points of the terminal points?

temrinal points