Question

1. if ∠abc = 50° and ∠cbd = 30°, then ∠abd =? mark only one oval. 20° 50° 80° 100° 14. two angles that add up to 90° are called: mark only one oval. supplementary complementary vertical linear pair 15. two angles that add up to 180° are: mark only one oval. supplementary complementary vertical adjacent

Explanation:

Step1: Find ∠ABD

Since ∠ABD = ∠ABC+∠CBD, and ∠ABC = 50° and ∠CBD = 30°, then ∠ABD=50° + 30°
∠ABD = 80°

Step2: Recall angle - sum definitions

For two angles that add up to 90°, by definition, they are complementary angles.
For two angles that add up to 180°, by definition, they are supplementary angles.

Answer:

1. C. 80°
2. B. Complementary
3. A. Supplementary