Answer:
x = 6
Step-by-step explanation:
All angles together equal 360
Us this to set up your formula
360 = 111 + 111 + 69 + 12x-3
360 = 288 + 12 x
360 - 288 = 12x
72 = 12x
72/12 = x
6 = x
You could also use the fact that angle t and r are equal to set your formula up as
69 = 12x-3
69+3=12x
72=12x
72/12=x
6=x
