Answer:
The perimeter is 37.8 cm
Explanation:
The perimeter of a sector is the sum of the length of the arc and 2 radii
The formula for the length of the arc is;
theta/360 * 2 * pi * r
126/360 * 2 * 3.142 * 9 = 19.80 cm
We now add the 2 radii
That gives;
19.80 + 2(9)
19.80 + 18
= 37.8 cm