Question

please solve this for me!! its from khan academy

Answer 1

Given:

The given triangle ABC is a right angled triangle.

The length of AC is 4 units.

The measure of ∠B is 20°

We need to determine the length of BC.

Length of BC:

The length of BC can be determined using the trigonometric ratio.

Thus, we have;

$tan \ \theta=\frac{opp}{adj}$

From the figure, the side opposite to the angle is AC and adjacent is BC.

Substituting opp = AC and adj = BC, we get;

$tan \ 20^{\circ}=\frac{AC}{BC}$

Substituting AC = 4, we have;

$tan \ 20^{\circ}=\frac{4}{BC}$

Simplifying, we have;

$BC=\frac{4}{tan \ 20^{\circ}}$

$BC=\frac{4}{0.364}$

$BC=10.99$

Thus, the length of BC is 10.99 units.