Question

Can you help me with finding perimeter of this sector fragment?

Just Q8. I'll ask more questions if I
need more help.

-Fish

Answer 1

The radius of the outer circle `R=45cm`

The radius of the concentric inner circle `r=22cm`

So the total area in between their perimeter

`=pi(R^2-r^2)=pi(45^2-22^2)cm^2`

So area of the shaded portion

`=pi(45^2-22^2)xx85/360=11.43cm^2`

perimeter of the shaded part

`=2pi(R+r)xx85/360+2(R-r)`cm

`=2pi(45+22)xx85/360+2xx(45-22)~~145.4`cm