Question

Photo attached with instructions

Answer 1

Explanation:

using cosine rule,

BC²= AC² + BC² - 2*AC*BC*COSc

= 13² + 6² - 2*13*6*-cos(180-91)

= 169 + 36 - (-2.72)

= 202.28

√BC² = √202.28

BC = 14.22

BC = 14.20cm to nearest tenth