Answer:
18π + 90
Step-by-step explanation:
The perimeter is the sum of quarter of the circumference and 2r , that is
P = 2πr + (45 + 45)
= 2 × π × 36 × [tex]\frac{1}{4}[/tex] + 90
= 2 × π × 9 + 90
= 18π + 90
