Do ex. 9 (chapter 6) in your book.
and do this quiz: https://quizizz.com/join?gc=50128780
Remember:
Do you have the degrees of the angle and you want to know the ratio?
Use sin, cos, tan
Do you have the ratio and you want to know the size of the angle?
Use sin-1 (shift-sin), cos-1 (shift-cos), tan-1 (shift-tan)