Answer:
m = 9
Explanation:
The three angles shown all add up together to 180° . The angle in the middle is marked with a little square that means it is 90°. So we can write an equation:
4m-6+90+6m+6=180°
combine like terms.
10m + 90° = 180°
subtract 90
10m = 90
divide by 10
m = 9