Part A
The small red arcs indicate that angles PQS and RQS are congruent.
13x - 1 = 2(6x + 4)
13x - 1 = 12x + 8
x = 9
m<PQR = 13x - 1 = 116
m<RQS = 6x + 4 = 6(9) + 4 = 58
m<PQS = 116 - 58 = 58
Part B
12^2 + (OH)^2 = 13^2
144 + (OH)^2 = 169
(OH)^2 = 25
OH = 5
r = OH = 5
Part C
WZ/ZY = WX/XY
24/12 = 30/XY
2 = 30/XY
2(XY) = 30
XY = 15