Step 1) Identify the clues/properties provided in the question
By observing the diagram provided, we can tell that:
- Statement 1: ∠B = ∠C (Vertically opposite angles)
- Statement 2: The sum of ∠C and the measure of the adjacent angle (43°) is 180° because those angles form a straight line.
Step-2) Create equations based on the properties identified
When converting the verbal equation into a numerical/linear equation of the second statement, we have ∠C + 43° = 180°
From the previous step, we also had: ∠B = ∠C
Step-3) Solve the equations and find the measure of the angles
⇒ ∠C + 43° - 43 = 180° - 43
⇒ ∠C = 180° - 43 = 137°
Therefore, ∠B = 137° because of the equation: ∠B = ∠C