Question

I don't even know how to figure this out. I don't have a formula for this

Answer 1

`\sin\theta=(15)/(17)`

`?=15`

Explanation:

Use the trigonometry formula

`\cos^2\theta+\sin^2\theta=1`

You are given that

`\cos \theta=(8)/(17)`

Substitute into the first formula

`\left((8)/(17)\right)^2+\sin^2\theta=1\\ \\(64)/(289)+\sin^2\theta=1\\ \\\sin^2\theta=1-(64)/(289)=(289-64)/(289)=(225)/(289)\\ \\\sin \theta=\pm (15)/(17)`

Angle
`\theta` is acute angle, then the sine of this angle is positive and

`\sin\theta=(15)/(17)`