Let’s take a rectangle
And add a semicircle on top of side CD & AB
What will be the area of total figure?
Area of total figure = Area of rectangle + Area of top semicircle + Area of bottom semicircle.
So, area gets added
Let’s take some values & actually solve it
What will be the area of the figure given below?
Here,
Area of total Figure = Area of rectangle + Area of top semicircle + Area of bottom semicircle
Here, Both semicircle will have the same diameter,
So, their area will be the same
∴ Area of total figure = Area of rectangle + 2 × Area of semicircle
Let’s find them out separately
Area of rectangle
Length = l = AB
= 20 cm
Breadth = b = BC
= 5 cm
Area of rectangle ABCD = l × b
= AB × BC
= 20 × 5
= 100 cm 2
Area of semi-circle
Diameter = 20 cm
Radius = r = Diameter/2
= 20/2
= 10 cm
Now,
Area of semi-circle = (Area of circle)/2
= πr 2 /2
= (3.14 (10) 2 )/2
= (314 × 100)/(100 × 2)
= 314/2
= 157 cm 2
Now,
Area of figure = Area of rectangle ABCD + 2 Area of semi-circle
= 100 + 2 × (157)
= 100 + 314
= 414 cm 2
∴ Area of given figure is 514 cm 2