Question

In ΔQRS, q = 1.3 inches, r = 1.6 inches and ∠S=157°. Find the length of s, to the nearest 10th of an inch.

Answer 1

2.8

Explanation:

using cosine rule

`s^(2)` =
`1.3^(2) + 1.6^(2) - 2(1.3)(1.6)cos 157`

s =
`√(8.0793)` = 2.842 = 2.8