im really stuck on these, can anyone help me and also explain how to solve them:

Question

Find the exact values of s in the given intervals that have the given circular function values.
1. [pi/2, pi]; sin s=sqrt2/2
2. [pi/2, pi]; cos s=-sqrt3/2
thnks:)

Answer 1

sqrt 2 is the legs of a 45,45, 90 triangle, hypotenuse is 2

sqrt 3 is the side opposite the 60 degree angle in a 30,60, 90 triangle. (legs are 1 and sqrt 3, hypotenuse is 2)

Learn those right triangles by heart. They come up constantly.

Answer 2

how does that help me find s though..