Since angle x and the angle measure given are on the same line, they have to add up to 180 degrees. So, to start this problem, take what is given and set it equal to 180 degrees.
x - 36 + x = 180
Now simplify the equation.
x - 36 + x = 180 ******* Add 36 to both sides.
x + x = 216 ******* Now add together the x's
2x = 216 ******* Divide both sides by 2.
x = 108
108 degrees is your answer, but you should still go back and check your work. Plug in the value of x to see if it works in the equation.
x - 36 + x = 180 **** plug in 108 for x
108 - 36 + 108 = 180 ****** simplify to see if it equals 180
72 + 108 = 180
180 = 180
******** This answer does work because when x is plugged back into the equation, both sides are equal. **********************************************
