Answer: A three-sided polygon is a triangle.
There are several different types of triangle (see diagram), including: Equilateral – all the sides are equal lengths, and all the internal angles are 60°. Isosceles – has two equal sides, with the third one a different length.
Step-by-step explanation:
Point D is the midpoint of the outer circle that we aim to find the area of
The circle has a diameter of WZ and radii of WC and CZ
We know that YZ=YD=10 cm
Let DC be

and CY be

The radius of the outer circle can be written as

or

which we can equate to find the value of





Therefore, the radius of the circle is

And hence the area of the circle is

=324