Answer:
x=12
Step-by-step explanation:
The three angles add to a straight line which is 180 degrees
20 + 6x-2 + 90 = 180
Combine like terms
108 + 6x = 180
Subtract 108 from each side
108+6x-108 = 180-108
6x =72
Divide each side by 6
6x/6 = 72/6
x=12
Its very easy just take y2 - y1 over x2 - x1 and solve
