Question

Solve the triangle.

a= 10.0 ft, b= 11.0 ft, c = 13.0 ft
What is the measure of angle A?
A=⁰
(Round to two decimal places as needed.)
What is the measure of angle B?
B =°
(Round to two decimal places as needed.)
What is the measure of angle C?
c=°
(Round to two decimal places as needed.)
...

Answer 1

Below in bold.

Explanation:

Using the Cosine Rule:

a^2 = b^2 + c^2 - 2bc cos A

10^2= 11^2 + 13^2 -2.11.13 cos A

cos A = (11^2 + 13^2 - 10^2) / (2*11*13)

= 0.66434

m < A = 48.368 degrees

= 48.37 degrees to 2 D. P's.

By the Sine Rule:

a / sin A = b / sin B

10 / sin 48.368 = 11 / sin B

sin B = 11 * sin 48.368 / 10

= 0.82217

m < B = 55.303

= 55.30 degrees to 2 D,P's

So, m < C = 180 - 48.37 - 55.30

= 76.33 degrees