Question

Which expressions can be used to find m∠ABC? Check all that apply.

Answer 1

`\cos^(-1)((6.3)/(9.8))`

`\sin^(-1)((7.5)/(9.8))`

Explanation:

Recall the mnemonics SOH-CAH-TOA

The sine ratio is the length of the opposite side expressed over the hypotenuse.

`\sin m\angle ABC=(7.5)/(9.8)`

Take the sine inverse of both sides to get;

`m\angle ABC=\sin^(-1)((7.5)/(9.8))`

The cosine ratio is the length of the adjacent side expressed over the hypotenuse.

`\cos m\angle ABC=(6.3)/(9.8)`

Take the cosine inverse of both sides to get;

`m\angle ABC=\cos^(-1)((6.3)/(9.8))`