Answer: x = - 10
Step-by-step explanation:
a) Linear Pair: 138 + ∠a = 180° --> ∠a = 42°
b) Triangle Sum Theorem: ∠a + 2∠b = 180° --> ∠b = 69°
c) Vertical Angles Theorem: ∠b = ∠c --> ∠c = 69°
d) Congruent sides implies congruent angles: ∠c = ∠d --> ∠d = 69°
∠2) Triangle Sum Theorem: ∠c + ∠d + ∠2 = 180°
69° + 69° + ∠2 = 180°
∠2 = 42
x) m∠2 = 42
x + 52 = 42
x = -10
