Answer:
First, we need to find the missing side which is BC ( using pythagorean theorem)
AB² + BC² = AC²
=> 16² + BC² = 20²
=> BC² = 20² - 16² = 144
=> BC = √144 = 12
Now apply the formulars:
Just to make things easier, let's point out exactly what will the hypotenuse, opposite side and adjacent side.
So in this case:
The hypotenuse will be AC
The opposite side (of angle A) is BC
The adjacent side (of angle A) is AB
Therefore:
sin A = opposite/hypotenuse = BC/AC = 12/20 = 3/5
cos A = adjacent/hypotenuse = AB/AC = 16/20 = 4/5
tan A = opposite/adjacent = BC/AB = 12/16 = 3/4