Answer:
x = 17, A = 114 degrees
Explanation:
Angles A and B are the same. That means you can set their equations equal to each other to solve for x.
6x + 12 = 3x + 63
3x = 51
x = 17
Plug that value in the equation for A to find its value:
A = 6(17) + 12
A = 114
Hope this helps!