Answer: Answer is in the steps
Explanation:
If we given the angle measure in variables then we will sum them up equal 180 and solve for x to determine the angle measure.
9x + x +x+4 = 180
11x + 4 = 180
-4 -4
11x = 176
x=16
In this case we can find the angle measures by using the expressions.
x = 16 degrees
x+4 = 20 degrees
9x = 144 degrees