Question

Find the measure of the indicated angle. Need help please.
I need explanation

Answer 1

20.12m

Explanation:

180 - (12 + 61) = 107° = ∡B

`(23)/(sin(107)) = (a)/(sin(61))` *Cross Multiply*

`a(sin(107)) = 23(sin(61))` *Divide by sin(107)*

`a = (23(sin(61)))/(sin(107))` *Solve*

a = BC ≈ 20.12m

Answer 2

BC =21.03540021

Explanation:

We know the measure of angle B since the sum of the angles of a triangle add to 180

A + B+ C = 180

61+ B + 12 =180

B = 180 - 12 -61

B =107

Then we can use the law of sines to find BC

sin B sin A

-------- = -------------

AC BC

sin 107 sin 61

-------- = -------------

23 BC

Using cross products

BC sin 107 = 23 sin 61

BC = 23 sin 61/ sin 107

BC =21.03540021