∠A and ∠ B ∠B are vertical angles. If m ∠ A = ( 2 x − 10 ) ∘ ∠A=(2x−10) ∘ and m ∠ B = ( x + 8 ) ∘ ∠B=(x+8) ∘ , then find the measure of ∠ A ∠A.

Answer 1

m∠A = m∠B (Def. of Vertical Angles)

2x - 10 = x + 8 (Substitution)

x = 18 (Subtract x and add 10 on both sides)

m∠A = 2(18) - 10 = 36 - 10 = 26º