Question

А A
B
D
If m_ABD = 64°, and mZCBD = 30°,
then m ABC = [?]°

Answer 1

34 degrees

Explanation:

If ABD = 64, and CBD is 30, we can use PWP( Part Whole Postulate)

Step 1.CBD + ABC = ABD

Step 2. Substitute

30 + ABC = 64

Step 3. Isolate ABC

34 = ABC

ABC is 34 degrees

Answer 2

9514 1404 393

Answer:

34°

Explanation:

It should be fairly intuitive that the two smaller angles add to give the value of the larger one. (Even if it's not, the angle sum theorem tells you this is true.)

∠ABC + ∠CBD = ∠ABD

∠ABC + 30° = 64°

∠ABC = 34° . . . . . . . . . subtract 30° from both sides of the equation