Answer:
Step-by-step explanation:
The circumference of circle G is 2pi, which means that HJ is equal to 81/360*2pi = 9pi/20, which means that RJ is equal to 18pi/20-9pi/20 = 9pi/20. Therefore, RHJ is equal to the circumference of the area minus RJ, which is equal to 40pi/20 - 9pi/20 = 31pi/20
I hope this helps