Circle Area and Circumference

Full circle perimeter is 2πρ so here is 2πPO => 2π5 = 10π but we have 3/4 of full curcle so 10π(3/4)=15/2π 

15/2π is the perimeter of circular disk we want and PO + OQ so Finally perimeter of the shaded region is:

15/2π + 5 + 5 = 15/2π + 10 or if π= ~3.14 we have ~ 33.5619449019234493 

Hope this helps!

Thank you so much