Question

Find the length of side BC.

Give your answer to 3 significant figures.
C
A
71°
B

Answer 1

19.4°

Explanation:

I put the image of how I did it if you don't understand let me know

Answer 2

BC ≈ 19.4 cm

Explanation:

using the cosine ratio in the right triangle

cos71° =
`(adjacent)/(hypotenuse)` =
`(AB)/(BC)` =
`(6.3)/(BC)` ( multiply both sides by BC )

BC × cos71° = 6.3 ( divide both sides by cos71° )

BC =
`(6.3)/(cos71)` ≈ 19.4 cm ( to 3 sig. figs )