Question

A sports field has a shape that consists of semi circle and a rectangle as shown on the diagram on the right. The width of the field is 20m and its longest lengths measures 40 m. Find the area and the perimeter of the field.

Answer 1

You know that the diameter of the circle is 20 m, and the two ends of the field make the full circle. The perimeter of a circle is given by the equation (pi)x(diameter)
So total perimeter =
= circle + the two long sides of the field
= (3.14159265)x 20 + 40m +40m
=

Answer 2

The vertical distance across the semi-circle = Dia./2 = 20/2 = 10 m.,
The width of the rectangle = 20 m.,
The length of the rectangle = 40-10 = 30 m.,

A = pi*r^2/2 + L*W = (3.14*10^2/2) + 30*20 = 757 m^2.
P = Pi*Dia./2 + 2L + W = (3.14*20/2) + 2*30 + 20 = 111.4 m.