Question

In `triangle ABC, a=5, b=12, c=13`, how do you find the cosine of each of the angles?

Answer 1

Since `5^2+12^2 = 13^2`, this is a right triangle with hypotenuse `c=13`.

Explanation:

`cos A =b/c = 12/13`

`cos B = a/c = 5/13`

`cosC = cos90^@ = 0`