Question

In the right triangle shown, \angle A = 30^\circ∠A=30 ∘ and AB = 4AB=4. How long is BCBC?

Answer 1

BC=2

Explanation:

Consider right triangle ABC with right angle C and angle A of the measure of 30°. In this triangle, AB=4.

Theorem: The leg opposite to the 30° angle is half of the hypotenuse.

Note that AB=4 is the hypotenuse, angle A has the meausre of 30°, then the leg BC is half of AB:

`BC=(1)/(2)AB=(1)/(2)\cdot 4=2.`