Angle Addition and Angle Bisector

Front

What is the Angle Addition Postulate?

Back

The Angle Addition Postulate states that if point D is in the interior of angle ABC, then m∠ABD + m∠DBC = m∠ABC.

Front

Define an Angle Bisector.

Back

An Angle Bisector is a ray that divides an angle into two congruent angles.

Front

What is the measure of a Right Angle?

Back

A Right Angle measures exactly 90 degrees.

Front

If m∠A = 25 degrees and m∠B = 65 degrees, what is m∠C if A, B, and C are angles on a straight line?

Back

m∠C = 180 - (m∠A + m∠B) = 180 - (25 + 65) = 90 degrees.

Front

What is the sum of the measures of angles in a triangle?

Back

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

Front

If two angles are complementary, what is the relationship between their measures?

Back

The measures of two complementary angles add up to 90 degrees.

Front

If m∠1 = 40 degrees, what is m∠2 if ∠1 and ∠2 are supplementary?

Back

m∠2 = 180 - m∠1 = 180 - 40 = 140 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

Find x if m∠A + m∠B = 180 degrees and m∠A = 70 degrees.

Back

x = 180 - m∠A = 180 - 70 = 110 degrees.