Chapter 1 Vocab

Undefined Term

A bacic figure that is not defined in terms of other figures. The undefined terms are point, line, and plane.

Point

An undefined term in geometry,it names a location and has no size.

Line

An undefined term in Geometry, a line is a straight path that has no thickness and extends forever.

Plane

An undefined trerm in Geometry, it is a flat surface that has no thickness and extends forever.

Collinear

Points that lie on the same line.

Coplanar

Points that lie on the same plane.

Segment

A part of a line consisting of two endpoints and all the points between them.

Endpoint

A point at an end of a segment or starting point of a ray.

Ray

A part of a line that starts at an end point and extends forever in one direction.

Opposite Rays

Two rays that have a common endpoint and form a line.

Postulate

A statement that is accepted as true withiout proof. Also called an Axiom.

Coordinate

A number used to identify the location of a point. On a number line, one coordinateis used. One a coordinate plane,two coordinates are used, calles x-v=coordinate and the y-coordinate. In space, three coordinates and used, called the x-coordinate, the y-c

Distance between two points

The absolute value of the distance of the coordinate of the points.

Length

The distance between the two endpoints of a segment.

Congruent Segments

Two segments that have the same length.

Construction

A method of creating a figure that is considered to be mathematically precise. Figures may be constructed by using a compass and a straightedge,geometry software, or paper folding.

Between

Given three points, A,B,and C,if B is between A and Cif and only if all three of the points line, and AB+BC=AC.

Midpoint

The point that divides a segment into two congruent segments.

Bisect

To divide into two congruent parts.

Segment Bisector

A line,a ray, or a segment that divides a segment into two congruent segments.

Angle

A figure formed by two rays with a common endpoint.

Vertex

The common endpoint of the sides of the angle.

Interior of an angle

The set of all points inside an angle.

Exterior of an angle

The set of all points outside an angle

Measure of an angle

Angles are measured in degrees. A degree is 1/360 of a complete circle.

Degree

A unit of angle measure;one degree is 1/360 of a circle.

Acute Angle

An angle that measure greater that 0 degrees and less than90 degrees.

Right Angle

An angle that measures 90 degrees.

Obtuse Angle

An angle that measures greater than 90 degrees but less than 180 degrees.

Straight Angle

a 180 degree angle.

Congruent Angles

Angles that have the same measure.

Angle Bisector

A ray that divides an angle into two congruent angles.

Adjacent Angles

Two angles in the same plane with a common vertex and a common side,but no interior points.

Linear Pair

A pair of adjacent angles whose noncommon sides opposite rays.

Complementary Angles

Two angles whose measures have a sum of 90 degrees.

Supplementary Angles

Two angles whose measures have a sum of 180 degrees.

Vertical angles

The nonadjacent angles formed by two intersecting lines.

Perimeter

The sum of the side lengths of a closed plane figure.

Area

The number of nonoverlappng unit squares of a given sizethat will exactlycover the interior of a plane figure.

Base

Any side of a triangle.

Height

A segment from a vertex that forms a right triangle witha linecontaining the base.

Diameter

A segment that has endpoints on the circle and that passes through the center of the circle;also the length of that segment.

Radius of a circle

A segment whose endpoints are the center of the circle and on the circle; the distance from the center of a circle to any point of the circle.

Circumference

The distance around a circle.

Pi

The ratio of the circumference of a circle to itsdiameter, denoted by the Greek letter pi. The value of pi is irrational, often approximated by 3.14 or 22/7.

Coordinate Plane

A plane that is divided into four regions bu a horizontal line called the x-axisand a vertical line called the y- axis.

Leg

One of the two sides of the right triangle that form the right triangle.

Hypotynuse

The side opposite the right angle in a right triangle.

Transformaion

A change in a position, size, or shape of a figure or graph.

Preimage

The original figure in a transformation.

Image

A shape that results from a transformation or a figure known as a preimage.

Reflection

A transformation across a line, called of reflection, such a that the line of reflection is the perpendicular bisector of each segment joining each point and its image.

Rotation

A trasformation about a point P,also known as the center of rotation, such that each point and its image are the same distance from P. All of the angles with vertex P formed by a point and its image are congruent.

Translation

A trasformation that shifts or slides every point of a figure or graph the same distance on the same direction.

Undefined Term

A bacic figure that is not defined in terms of other figures. The undefined terms are point, line, and plane.

Point

An undefined term in geometry,it names a location and has no size.

Line

An undefined term in Geometry, a line is a straight path that has no thickness and extends forever.

Plane

An undefined trerm in Geometry, it is a flat surface that has no thickness and extends forever.

Collinear

Points that lie on the same line.

Coplanar

Points that lie on the same plane.

Segment

A part of a line consisting of two endpoints and all the points between them.

Endpoint

A point at an end of a segment or starting point of a ray.

Ray

A part of a line that starts at an end point and extends forever in one direction.

Opposite Rays

Two rays that have a common endpoint and form a line.

Postulate

A statement that is accepted as true withiout proof. Also called an Axiom.

Coordinate

A number used to identify the location of a point. On a number line, one coordinateis used. One a coordinate plane,two coordinates are used, calles x-v=coordinate and the y-coordinate. In space, three coordinates and used, called the x-coordinate, the y-c

Distance between two points

The absolute value of the distance of the coordinate of the points.

Length

The distance between the two endpoints of a segment.

Congruent Segments

Two segments that have the same length.

Construction

A method of creating a figure that is considered to be mathematically precise. Figures may be constructed by using a compass and a straightedge,geometry software, or paper folding.

Between

Given three points, A,B,and C,if B is between A and Cif and only if all three of the points line, and AB+BC=AC.

Midpoint

The point that divides a segment into two congruent segments.

Bisect

To divide into two congruent parts.

Segment Bisector

A line,a ray, or a segment that divides a segment into two congruent segments.

Angle

A figure formed by two rays with a common endpoint.

Vertex

The common endpoint of the sides of the angle.

Interior of an angle

The set of all points inside an angle.

Exterior of an angle

The set of all points outside an angle

Measure of an angle

Angles are measured in degrees. A degree is 1/360 of a complete circle.

Degree

A unit of angle measure;one degree is 1/360 of a circle.

Acute Angle

An angle that measure greater that 0 degrees and less than90 degrees.

Right Angle

An angle that measures 90 degrees.

Obtuse Angle

An angle that measures greater than 90 degrees but less than 180 degrees.

Straight Angle

a 180 degree angle.

Congruent Angles

Angles that have the same measure.

Angle Bisector

A ray that divides an angle into two congruent angles.

Adjacent Angles

Two angles in the same plane with a common vertex and a common side,but no interior points.

Linear Pair

A pair of adjacent angles whose noncommon sides opposite rays.

Complementary Angles

Two angles whose measures have a sum of 90 degrees.

Supplementary Angles

Two angles whose measures have a sum of 180 degrees.

Vertical angles

The nonadjacent angles formed by two intersecting lines.

Perimeter

The sum of the side lengths of a closed plane figure.

Area

The number of nonoverlappng unit squares of a given sizethat will exactlycover the interior of a plane figure.

Base

Any side of a triangle.

Height

A segment from a vertex that forms a right triangle witha linecontaining the base.

Diameter

A segment that has endpoints on the circle and that passes through the center of the circle;also the length of that segment.

Radius of a circle

A segment whose endpoints are the center of the circle and on the circle; the distance from the center of a circle to any point of the circle.

Circumference

The distance around a circle.

Pi

The ratio of the circumference of a circle to itsdiameter, denoted by the Greek letter pi. The value of pi is irrational, often approximated by 3.14 or 22/7.

Coordinate Plane

A plane that is divided into four regions bu a horizontal line called the x-axisand a vertical line called the y- axis.

Leg

One of the two sides of the right triangle that form the right triangle.

Hypotynuse

The side opposite the right angle in a right triangle.

Transformaion

A change in a position, size, or shape of a figure or graph.

Preimage

The original figure in a transformation.

Image

A shape that results from a transformation or a figure known as a preimage.

Reflection

A transformation across a line, called of reflection, such a that the line of reflection is the perpendicular bisector of each segment joining each point and its image.

Rotation

A trasformation about a point P,also known as the center of rotation, such that each point and its image are the same distance from P. All of the angles with vertex P formed by a point and its image are congruent.

Translation

A trasformation that shifts or slides every point of a figure or graph the same distance on the same direction.