Question

Find all the missing sides and angles of this triangle.

А
7
B
70°
Show your work for full credit. You are finding the measure of angle A, side length of AC and side
Show Your Work
I

Answer 1

A = 20°

AC = 6.6

BC = 2.4

Explanation:

Given:

B = 70°

C = right angle = 90°

AB = 7

Required:

A, AC, and BC

Solution:

✔️A = 180 - (90 + 70) (sum of triangle)

A = 20°

✔️Use trigonometric function to find AC:

Refernce angle = 70°

Opp = AC

Hypotenuse = 7

Apply SOH,

sin 70 = Opp/Hyp

sin 70 = AC/7

7 * sin 70 = AC

6.57784835 = AC

AC = 6.6 (nearest tenth)

✔️Use trigonometric function to find Bc:

Refernce angle = 70°

Adj = BC

Hypotenuse = 7

Apply CAH,

cos 70 = Adj/Hyp

cos 70 = BC/7

7 * cos 70 = BC

2.394141 = BC

BC = 2.4 (nearest tenth)