Area of a Semi Circle

Introduction:-
In mathematics (more specifically geometry), a semicircle is a two-dimensional geometric shape that forms half of a circle. Being half of a circle's 360°, the arc of a semicircle always measures 180°. A triangle inscribed in a semicircle is always a right triangle.


The semi circular looks liek the following image.

The formula used to calculate the area of semicircle is `pi/2 r^2` .

Solved Problems:-

Problem 1:-

Calculate the area is semi circle, which has the radius of 6 centimeter.

Solution:-

The formula used to calculate the area of the semi circle is `pi/ 2 r^2` .

Given the radius of the semi circle is 6 centimeter.

Area of semi circle = `pi/ 2 r^2.`

Plug-in the value of radius in the formula we get

`= pi/ 2 6^2` .

`6^2` can be written as 6 * 6 = 36.

So the area of the semi circle is `18 pi` .


Problem 2:-

Calculate the area is semi circle, which has the radius of 12 centimeter.

Solution:-

The formula used to calculate the area of the semi circle is` pi/ 2 r^2` .

Given the radius of the semi circle is12 centimeter.

Area of semi circle =` pi/ 2 r^2` .

Plug-in the value of radius in the formula we get

= `pi/ 2 12^2` .

`12^2` can be written as 12 * 12 = 144.

So the area of the semi circle is `72 pi` .

Problem 3:-

Calculate the area is semi circle, which has the diameter of 4 centimeter.

Solution:-

The formula used to calculate the area of the semi circle is` pi/ 2 r^2` .

Given the diameter of the semi circle is 4 centimeter.

Radius is half of the diameter so the radius is `4 / 2 = 2` .

Area of semi circle = `pi/ 2 r^2.`

Plug-in the value of radius in the formula we get

= `pi/ 2 2^ 2` .

`2^2` can be written as 2 * 2 = 4.

So the area of the semi circle is `2 pi.`