Geometric Terms

7 Math: Sections 7-1 and 7-2

Lines and Planes

Point - indicates a location in space.

Line - A series of points that extend forever in both directions.

Ray - A part of line that goes forever in one direction.

Segment - A part of a line that is between 2 endpoints.

A

A B

C D

X Y

Plane

A flat surface that extends indefinitely in all directions and has no thickness.

A piece of paper is like a plane that you write on.

What are some other planes in the classroom?

Types of Lines

Intersecting Lines - Have exactly one point in common because they meet one time.

Parallel Lines - Are in the same plane and never intersect.

Skew Lines - Lie in different planes, and never intersect and are not parallel.

Practice Naming Line Segments

Name a pair of intersecting segments.

Name a pair of parallel segments.

Name a pair of skew segments.

Angles

An angle is formed by 2 rays with a common endpoint.

Vertex - is the point of intersection of the 2 rays.

Name with Angle Sign, followed by 3 capital letters with the vertex in the middle.

XY

Types of Angles

Acute: Between 0 and 90 degrees.

Right: 90 degrees

Obtuse: between 90 and 180 degrees

Straight: 180 degrees

Pairs of Angles

Complementary: Pairs of angles whose sum is 90 degrees

Supplementary: Pairs of angles whose sum is 180 degrees

Adjacent: Share a vertex and a side

Vertical: Formed by 2 intersecting lines and are opposite each other (in the X)

Congruent: Have equal measures

Identifying Angles

Obtuse

Acute

Straight

Right

Identifying Angles

Complementary

Supplementary

Vertical

Adjacent