The Angle Addition Postulate

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

If m∠EFG = 37° and m∠EFH = 19°, what is m∠HFG?

Back

m∠HFG = m∠EFG + m∠EFH = 37° + 19° = 56°.

Front

What equation would you use to find x if m∠ABC = 147° and m∠ABD = 21x - 5, m∠DBC = 10x - 3?

Back

21x - 5 + 10x - 3 = 147.

Front

Given m∠QST = 135°, what equation would you use to find x if m∠QSR = 3x + 1 and m∠RST = 2x - 6?

Back

3x + 1 + 2x - 6 = 135.

Front

Find the value of ∠A if m∠B = 90° and m∠C = 65°.

Back

∠A = 180° - (90° + 65°) = 25°.

Front

If m∠ABC = 103°, find m∠ABD if m∠DBC = 57°.

Back

m∠ABD = m∠ABC - m∠DBC = 103° - 57° = 46°.

Front

What is the sum of the angles in a triangle?

Back

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

Front

Define complementary angles.

Back

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

Front

Define supplementary angles.

Back

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

Front

If m∠1 + m∠2 = 90°, what can you conclude about angles 1 and 2?

Back

Angles 1 and 2 are complementary.