Geometry Terms

Front

Parallel Lines

Back

Coplanar lines that never intersect.

Front

Collinear

Back

Points that lie on the same line.

Front

Obtuse Angle

Back

An angle with a degree measure greater than 90 and less than 180.

Front

Diagram showing supplementary angles.

Back

Illustration of two angles summing to 180 degrees.

Front

Linear Pair

Back

A pair of adjacent angles whose noncommon sides are opposite rays. Always supplementary.

Front

Adjacent Angle

Back

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

Front

The sum of two opposite interior angles equals the exterior angle in a triangle.

Back

This is a key concept in the Exterior Angle Theorem.

Front

Exterior angles are formed by extending one side of a triangle.

Back

They can also be outside the region between two transversals.

Front

Consecutive interior angles help in identifying parallel lines.

Back

They are supplementary when lines are parallel.

Front

Measure

Back

The size, length, or amount of something, typically as established by measuring.