What is the area of the shaded sector of the circle?

180π units²

Step-by-step explanation:

The shaded sector is 162/360 of the circle.  This is because the total number of degrees in the circle is 360 and the shaded portion is 162; this means it is 0.45 of the circle.

The area of a circle is given by A = πr², where r represents the radius of the circle.  This makes the area of this circle

A = π(20²) = 400π.

This makes the area of the sector

A = 0.45(400π) = 180π