Answer:
B.
A.
D.
Step-by-step explanation:
1.) Do 10 + 23 + x = 180. x = 147 Triangles add to 180, remember this or fail
2.) Do 64 + 38 + x = 180 to find the missing ∠G. G = 78
Now, a line is equal to 180 degrees. Remember this or you will fail. Do 180 - 78 to get your missing angle. 102 degrees
3.) Adjacent angles add up to equal 180, this is a very simple geometry concept. Remember it. 5x + 3 + 12x + 12 = 180
17x + 15 = 180
Subtract 15 from both sides to get 17x = 165
Divide both sides by 17 to get your x value of about 10