Question

In the figure below, m∠1 = x and m∠2 = x - 4. Which statement could be used to prove that x = 47?

Answer 1

The answer is C) m∠1 + m∠2 = 90

Explanation: So ∠1 is x and ∠2 is x-4

Basically you know than ∠3 is 90° ... And a straight line is 180° ..                            So technically we can just find out 180-90 is 90(the other angle 1 + 2).

To get 90° we'll add ∠1 and ∠2 in other ways, like technical thinking-

So you already know adding ∠1 and ∠2 is 90°. So ∠1 + ∠2 = 90°

In other words you can say m∠1 + m∠2 = 90