So I understand the equation is A = ab sin(c)

When given Area 25(squared), side a = 7, side b = 8, i need to find the sin of c.

I come up with 1/2 * 7 * 8 * sin(c)= 25

28 * sin(c) = 25

sin(c) = 25/28

Now, given the answer in the book (63.2 degrees), I am unsure of how to get this number from:

sin(c) = 25/28

c is the angle. if you're looking for sin (c) then you're fine. it's not measured in degrees.

with that said, to get the angle c you just find the arcsin(25/28) which you can put into a calculator as ~63 degrees

This post was edited by carteblanche on Jul 5 2015 09:06pm

Awesome! Thank you. Arcsin was the answer.