According to the Pythagorean Theorem,
hypotenuse^2 = leg^2 + leg^2
25^2 = 15^2 + leg^2
625 - 225 = leg^2
leg = 20
Since there is NO diagram, I am guessing at what angle ACB is.
sine(ACB) = 20 / 25 = .8
arc sine (.8) = 53.13 degrees
In case it should be the other angle, then it is
36.87 degrees
