Question

2. Find the measure of angle A to the nearest degree.

Answer 1

Answer:

37°

Step-by-step explanation:

we're going to use cosine rule In calculating for the value of angle A

note that cosine rule can be used when two sides are given with an included angle . from the diagram above, the two sides given are side AB and side AC and the included angle is A

Hence cosine rule

a^2 = AB^2+AC^2 - 2AB×AC Cos A

3.2^2= 2.1^2+4.6^2-2×2.1×4.6COSA

10.24 =4.41+21.16- 19.32 COSA

10.24 = 25.57-19.32COSA

10.24-25.57= -19.32COSA

-15.33= -19.32COSA

dividing bothsides by - 19.32

COSA= -15.33/19.32

COA= 0.79347826

A = COS^-1 (0.79347826)

A= 37.488

A= 37°

hope this helps!!