Chpt 5: Lesson 1 & 3: Angles and Triangles

Front

What is an angle?

Back

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

Front

What are complementary angles?

Back

Complementary angles are two angles whose measures add up to 90 degrees.

Front

What are supplementary angles?

Back

Supplementary angles are two angles whose measures add up to 180 degrees.

Front

What is a right angle?

Back

A right angle is an angle that measures exactly 90 degrees.

Front

What is an acute angle?

Back

An acute angle is an angle that measures less than 90 degrees.

Front

What is an obtuse angle?

Back

An obtuse angle is an angle that measures more than 90 degrees but less than 180 degrees.

Front

What are vertical angles?

Back

Vertical angles are the angles opposite each other when two lines intersect. They are always equal.

Front

What are corresponding angles?

Back

Corresponding angles are angles that are in the same position on two parallel lines cut by a transversal.

Front

What are alternate interior angles?

Back

Alternate interior angles are pairs of angles on opposite sides of a transversal that lie between two parallel lines. They are equal.

Front

What are alternate exterior angles?

Back

Alternate exterior angles are pairs of angles on opposite sides of a transversal that lie outside two parallel lines. They are equal.