Answer:
81
Explanation:
The angles shown are formed on a straight line
Angles formed on a straight line add up to 180
So m + m + 18 = 180
We've just created an equation that we can use to solve for m
So we can now solve for m
m + m + 18 = 180
Combine like terms
2m + 18 = 180
Subtract 18 from both sides
2m + 18 - 18 = 180 - 18
2m = 162
Divide both sides by 2
2m/2 = 162/2
m = 81