Answer: x = 40
The equation you would write would be 2x + x + 60 = 180.
This is because you have to add all the angles inside the triangle in order to get 180°. Then, you solve the equation.
2x + x + 60 = 180
Add all the like terms.
3x + 60 = 180
Subtract 60 on both sides.
3x = 120
Divide 3 on both sides.
x = 40
