Measuring and Constructing Angles/ Angle Bisectors

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 is the measure of a right angle?

Back

A right angle measures 90 degrees.

Front

What are acute angles?

Back

Angles that measure less than 90 degrees are called acute angles.

Front

What are obtuse angles?

Back

Angles that measure more than 90 degrees but less than 180 degrees are called obtuse angles.

Front

What is a straight angle?

Back

A straight angle measures exactly 180 degrees.

Front

What is the sum of angles in a triangle?

Back

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

Front

What is an angle bisector?

Back

An angle bisector is a ray that divides an angle into two equal parts.

Front

If m∠A = 25° and m∠B = 25°, what is m∠C in triangle ABC?

Back

m∠C = 180° - (m∠A + m∠B) = 180° - 50° = 130°.

Front

What is the relationship between complementary angles?

Back

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

Front

What is the relationship between supplementary angles?

Back

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