If I have a triangle with the hypotenuse side as 7, and the opposite side as 3, how would I find the angle? (This is a right triangle.)

......III
.....IIII
.7..IIIII
...IIIIII..3
..IIIIIII
_IIIIIIII<--90 degrees
Find this angle

Use the Pythagorean theorem.

c^2 = a^2 + b^2

b^2 = 49 - 9 = 40

b = ?