Question

Find the lengths of the missing sides if side a is opposite angle A, side b is opposite angle B, and side c is the hypotenuse.

cos(B) = 4/5 a=90

Answer 1

Explanation:

cosB = a/c = 4/5

so c = 5a/4 = 5*90/4 = 112.5

b² = c² - a² = 112.5² - 90² = 4556.25

b = 67.5