Scalene Triangle
A triangle with NO congruent sides
Isosceles Triangle
A triangle with TWO congruent sides
Equilateral Triangle
A triangle with THREE congruent sides.
Acute Triangle
A triangle with THREE acute angles
Obtuse Triangle
A triangle with ONE obtuse angle
Right Triangle
A triangle with ONE right angle
Equiangular Triangle
A triangle with THREE congruent angles.
Right-Scalene
Give one angle classification and one side classification for the given triangle.
Acute-Scalene
Give one angle classification and one side classification for the given triangle.
Obtuse-Scalene
Give one angle classification and one side classification for the given triangle.
Right-Isosceles
Give one angle classification and one side classification for the given triangle.
Acute-Isosceles
Give one angle classification and one side classification for the given triangle.
Obtuse-Isosceles
Give one angle classification and one side classification for the given triangle.
Equiangular-Equilateral
Give one angle classification and one side classification for the given triangle.
Parallel Lines
lines in the same plane that never intersect
Transversal
a line that intersects two or more lines
Corresponding Angles
Angles formed by a transversal cutting through 2 or more lines that are in the same relative position. If lines are parallel, these angles are congruent.
Alternate Interior Angles
Angles that are non-adjacent interior angles that lie on OPPOSITE sides of the transversal. If the lines are parallel, these angles are congruent.
Alternate Exterior Angles
Angles that are non-adjacent exterior angles that lie on OPPOSITE sides of the transversal. If lines are parallel, these angles are congruent.
Same Side Interior Angles
Angles that are non-adjacent interior angles that lie on the SAME side of the transversal. If lines are parallel, these angles are supplementary.
Interior Angles
Angles that lie in between the lines that are cut by the transversal
Exterior Angles
Angles that lie outside of both the lines that are cut by the transversal
collinear
Points that lie on the same line
coplanar
Points that lie in the same plane
endpoint
a point at one end of a segment or the starting point of a ray.
line
a straight path that has no thickness and extends forever.
Congruent
same shape and size
plane
a flat surface that has no thickness and extends forever.
point
a location and has no size. It is represented by a dot.
postulate
or axiom, is a statement that is accepted as true without proof.
ray
a part of a line that starts at an endpoint and extends forever in one direction.
segment
the part of a line consisting of two points and all points between them.
undefined terms
cannot be defined by using other figures.
Equal
same in value
distance
the absolute value of the differenceof the coordinates
length
distance between A and B ΜΆΜΆ
congruent segments
segments that have the same length
skew
two lines not parallel or two lines that do not intersect
midpoint
the point that bisects the segment into two congruent segments. the center point
bisect
divides
segment bisector
any ray, segment, or line that intersects a segment at its midpoint. It divides a segment into two equal parts at its midpoint.
angle
a figure formed by two rays, or sides, with a common endpoint
vertex
common endpoint
interior of an angle
The set of all points between the sides of the angle
exterior of an angle
the set of all points outside the angle.
measure
usually given in degrees.
degree
1 out of 360 of a circle
acute angle
an angle less then 90 degrees
right angle
a 90 degree angle
obtuse angle
an angle more then 90 degrees
straight angle
a 180 degree angle
congruent angles
angles that have the same measures
angle bisector
the line segment, line, or ray that bisects an angle
adjacent angles
two angles in the same plane with a common vertex and a common side, but no common interior points.
linear pair
a pair of adjacent angles whose noncommon sides are opposite rays
complementary angles
angles that add up to 90 degrees
supplementary angles
angles that add up to 180 degrees
vertical angles
two nonadjacent angles formed by two intersecting lines. opposite angles
coordinate plane
a plane that is divided into four regions by a horizontal line (x-axis) and a vertical line (y-axis)
intersection
the point where two lines meet
Transversal
line that intersects through two parallel lines
Perpendicular
lines that intersect to create 90 degree angles
Parallel
Lines that never intersect
oblique
neither parallel or perpendicular
Theorem
a statement that follows logically from definitions and principals