Answer:
238 
Explanation:
Important note: ∠FAH is an inscribed angle and arc mFGH is it's intercepted arc 
opposite angles in a quadrilateral formed inside of a circle area supplementary 
Supplementary meaning that they add up to equal 180 
So 13x + 15 + 8x - 3 = 180 
We now solve for x
step 1 combine like terms
13x + 8x = 21x
15 - 3 = 12 
12 + 21x = 180 
step 2 subtract 12 from each side
12 - 12 cancels out 
180 - 12 = 168 
21x = 168 
step 3 divide each side by 21
21x / 21 = x
168 / 21 = 8
we're left with x = 8 
Now we substitute 8 for x in 13x + 15 
13 ( 8 ) + 15
13 * 8 = 104 
104 + 15 = 119 
So ∠FAH = 119 
Recall that an included angle is equal to half the measure of its intercepted arc. 
so arc mFGH = 2 (119)
2 * 119 = 238 
Therefore your answer is A