Answer:
Step-by-step explanation:
∠ABC + ∠CBD = 90 so filling in the expressions for these angles:
(2x + 14) + (x + 7) = 90 and
3x + 21 = 90 and
3x = 69 so
x = 23. To find the measure of angle ABC in particular, we sub in a 23 for x:
x + 7 --> 23 + 7 = 30°, the last choice there.
