Answer:
6. 56.3 degrees.
7. 70.5 degrees.
Explanation:
6. We are given the opposite and adjacent side lengths, so we can use tangent to solve this (TOA = Tangent; Opposite over Adjacent).
tan(R) = 12 / 8
tan(R) = 3 / 2
R = cotan(3/2)
R = 56.309932474020213
So, the measure of angle R is about 56.3 degrees.
7. We are given the adjacent and the hypotenuse, so we can use cosine to solve this (CAH = Cosine; Adjacent over Hypotenuse).
cos(R) = 5 / 15
cos(R) = 1/3
R = sec(1/3)
R = 70.528779365509
So, the measure of angle R is about 70.5 degrees.
Hope this helps!