Answer:
m∠WXY is 142°
Step-by-step explanation:
The measure of the exterior angle at one vertex of a triangle equals the sum of the measures of the opposite interior angles to this vertex
In ΔXYZ
∵ ∠WXY is an exterior angle at the vertex X
∵ ∠Y and ∠Z are the opposite interior angles to the vertex X
→ By using the rule above
∴ m∠WXY = m∠Y + m∠Z
∵ m∠WXY = (2x - 2)°
∵ m∠Y = x° and m∠Z = 70°
→ Substitute them in the equation above
∴ 2x - 2 = x + 70
→ Subtract x from both sides
∵ 2x - x - 2 = x - x + 70
∴ x - 2 = 70
→ Add 2 to both sides
∵ x - 2 + 2 = 70 + 2
∴ x = 72
→ To find the m∠WXY, substitute x by 72 in its measure
∵ m∠WXY = 2(72) - 2
∴ m∠WXY = 144 - 2
∴ m∠WXY = 142°
