Complete Geometric Angle Proofs

Front

What is the definition of an angle?

Back

An angle is formed by two rays (sides of the angle) that share a common endpoint (the vertex).

Front

What is the Linear Pair Postulate?

Back

If two angles form a linear pair, then they are supplementary, meaning their measures add up to 180 degrees.

Front

What does the Vertical Angles Theorem state?

Back

Vertical angles are equal; if two angles are opposite each other when two lines intersect, they are congruent.

Front

What is the Corresponding Angles Postulate?

Back

If two parallel lines are cut by a transversal, then each pair of corresponding angles is equal.

Front

What is the definition of supplementary angles?

Back

Two angles are supplementary if the sum of their measures is 180 degrees.

Front

What is the definition of complementary angles?

Back

Two angles are complementary if the sum of their measures is 90 degrees.

Front

What is the definition of adjacent angles?

Back

Adjacent angles are two angles that share a common side and a common vertex but do not overlap.

Front

What is the definition of a transversal?

Back

A transversal is a line that intersects two or more lines at different points.

Front

What is the definition of congruent angles?

Back

Congruent angles are angles that have the same measure.

Front

What is the Alternate Interior Angles Theorem?

Back

If two parallel lines are cut by a transversal, then each pair of alternate interior angles is equal.