Find the area of the shaded field shown in figure.
We can clearly see that the figure comprises of a rectangle and a semi-circle.
Name the rectangle ABCD. Name the point where the
rectangle and the semi-circle meets as E.
Take any point F on the semi-circle, then we have
the semi-circle as EFD.
Now, area of the figure = Area of the semi-circle + Area of the rectangle.
Here, from the figure, Radius of the semi-circle = r = 6 - 4 = 2 m
∴ Area of the semi-circle = πr2/2 = 4π/2 = 2π
Also, area of the rectangle = Length × Breadth
= AB × BC
= 4 × 8 = 32 m2
∴Area of shaded region = Area of rectangle ABCD + Area of semi-circle DEF
= (32 +2π) m2