There are two triangles here. The larger one, and the smaller one inside the larger triangle.
Both triangles are similar, thus their sides will follow the same ratio. the ratio of the leg of the small triangle to the big triangle is 9/(31(1/2))
31 1/2 = 63/2
so,
the ratio of the leg of the small triangle to the big triangle is 9/(63/2)
When dividing by a fraction, you multiply the numerator by the reciprocal so,
9/(63/2) = (9*2)/63 = 18/63
18/63*63/2=9
Thus 18/63*h= 6 1/2 --> 18/63*h = 13/2
Once we divide both sides by 18/63 (which means multiplying 13/2 by 63/18), we see that h = 91/4 = 22.75
