Question

m∠bad = m∠bac + m∠cad
m∠bac = 20° given
m∠cad = 15° given
m∠bad = 20° + 15° substitution property of equality
m∠bad = 35° simplify
ruler postulate
angle addition postulate
linear pair postulate
angel congruence postulate

Explanation:

The Angle Addition Postulate states that if point C lies in the interior of ∠BAD, then m∠BAD = m∠BAC + m∠CAD. In the given problem, this postulate is used to find the measure of ∠BAD by adding the measures of the two non - overlapping angles ∠BAC and ∠CAD.

Answer:

Angle Addition Postulate