Find the value of b. Round your answer to the nearest tenth. The figure shows acute triangle A B C. The measure of angle B is 40 degrees. The length of side A B is 10. The length of side B C is 12. The length of side C A is b.

Side CA = 7.8

Step-by-step explanation:

Given:

Acute angled .

AB = 10

BC = 12

We can use cosine rule here to find the side AC = b

Formula for cosine rule:

Where  

a is the side opposite to

b is the side opposite to

c is the side opposite to

To the nearest tenth b = 7.8