Question

Using the right triangle below find the cosine of angle A.

Answer 1

For the given triangle, the cosine of angle A equals $\frac{1}{2}$.

Step-by-step explanation:

Step 1; In the given triangle, the opposite side has a length of 9 units, the adjacent side has a length of 3√3 units while the hypotenuse of the triangle measures 6√3 units. To calculate the cosine of angle A we divide the adjacent side by the hypotenuse side.

cos A = $\frac{adjacent side}{hypotenuse}$.

Step 2; Length of the adjacent side = 3√3 units.

Length of the hypotenuse side = 6√3 units.

cos A = 3√3 / 6√3

cos A = $\frac{1}{2}$.

To check we also have A = 60° and cos 60° = $\frac{1}{2}$.