Question

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

Answer 1

Answer:

20.12m

Step-by-step explanation:

180 - (12 + 61) = 107° = ∡B

$\frac{23}{sin(107)} = \frac{a}{sin(61)}$                     *Cross Multiply*

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

$a = \frac{23(sin(61))}{sin(107)}$                         *Solve*

a = BC ≈ 20.12m

Answer 2

Answer:

BC =21.03540021

Step-by-step 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