Angles and Triangles

Front

What is an angle?

Back

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

Front

What are the types of angles based on their measures?

Back

1. Acute: less than 90° 2. Right: exactly 90° 3. Obtuse: more than 90° but less than 180° 4. Straight: exactly 180°

Front

What is a triangle?

Back

A triangle is a polygon with three edges and three vertices.

Front

What are the types of triangles based on their angles?

Back

1. Acute triangle: all angles are acute. 2. Right triangle: one angle is a right angle. 3. Obtuse triangle: one angle is obtuse.

Front

What is the sum of the angles in a triangle?

Back

The sum of the interior angles in a triangle is always 180°.

Front

What are complementary angles?

Back

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

Front

What are supplementary angles?

Back

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

Front

If one angle is 30°, what is its complement?

Back

The complement is 60° (90° - 30°).

Front

If one angle is 120°, what is its supplement?

Back

The supplement is 60° (180° - 120°).

Front

What is a right angle?

Back

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