Answer:
#15 x ≈ 20.5
Explanation:
To find missing sides
1) find the reference angle
2) identify the information that is needed ( what are you given - opposite side, adjacent side, hypotenuse)
3) use that information to set up the trigonometric equation
#10
angle is 64, opposite side is 42, adjacent side is x
so you use tangent
tangent 64 = 42/x multiply by x
x tangent 64 = 42 divide by tangent 64
x = 42/tangent 64
x ≈ 20.5