Task 3: Use the diagram to find the measure of the angle indicated. Explain your reasoning.
B
50
mZABC =?

Answer:
m∠ABC = 130°
Step-by-step explanation:
Since ∠ABE ≅ ∠CBD [vertical angles]
(Vertical angles are the vertically opposite angles between two lines intersecting at a point.)
m∠ABE = m∠CBD = 50°
m∠ABE + m∠ABC = 180°
50 + m∠ABC = 180
m∠ABC = 130°
Therefore, m∠ABC = 130° will be the answer.