a. AB = FG, AC = FH, BC = GH
b. Remember that FG is the same as AB. This means that their values are equivalent. Therefore, FG = 9.
c. HG is the same as CB. If CB is 12, then HG must also be 12.
d. To solve for x, we'll need to set up an equation. We can do this by taking one of our known pairs of congruent sides and setting them equal to each other.
AB = FG
AB = 9
FG = 2x + 1
9 = 2x + 1
2x = 8
x = 4
Hope this helps!