Answer:
x = 40⁰
Step-by-step explanation:
The middle angle on the straight line = x (alternate angles).
x + x + 20 + 2x = 180⁰ (straight angles)
4x + 20⁰ = 180⁰ Add - 20⁰ to both sides
4x = 180⁰ - 20⁰
4x = 160⁰ Divide both sides by 4
x = 160⁰ / 4
x = 40⁰