Actually the formula for the area of a triangle is A = 1/2bh.
First step: multiply both sides by 2, to get rid of the 1/2.
2A = bh
Now divide both sides by b.
2A/b = h or h = 2A/b
Sine is also known as Opposite over hypotenuse.
I could be wrong but i graphed it out and 9 is C , 10 is A , and 11 is C Hopefully it's right