A semicircle is like taking half of a circle. Imagine slicing a circle right down the middle to create two equal pieces. Each of these pieces is called a semicircle. It’s as if you folded a round shape in half, and that folded part is now a semicircle. So, a semicircle is half of a circle.

## What Is a Semicircle?

A semicircle is a two-dimensional geometric shape that is half of a full circle. It is essentially half of the circular region obtained by cutting a complete circle along its diameter. The term “semi” means half, and in the case of a semicircle, it refers to the fact that it encompasses 50% of the area and arc length of a whole circle.

A semicircle has several key characteristics:

**Diameter:**The diameter of a semicircle is a straight line segment that passes through the center of the associated full circle and has both endpoints on the semicircle’s boundary. The diameter of the semicircle is twice the radius of the full circle.**Radius:**The radius of a semicircle is half the radius of the associated full circle. It is the distance from the center of the semicircle to any point on its boundary.**Arc Length:**The boundary of a semicircle forms a curved segment that is half the circumference of the associated full circle. The formula for calculating the arc length of a semicircle is $πr$, where $r$ is the radius of the semicircle.

## Area of a Semicircle

The area of a semicircle is half of the area of the corresponding full circle.

If r is the radius of the semicircle, then

Area of circle = πr²,

where π (pi) is a mathematical constant approximately equal to 3.14159.

So, the area of the semicircle is:

½ * πr²

or

Area of semicircle = πr² / 2

Therefore, the area of a semicircle is equal to half the area of a circle.

### How to Find the Area of a Semicircle

To find the area of a semicircle, you can use the following formula:

Area of a semicircle = (π * r²)/2

Where r is the radius of the semicircle, and π (pi) is a mathematical constant approximately equal to 3.14159.

Steps to find the area of a semicircle:

**Step1.** Measure the radius of the semicircle. The radius is the distance from the center of the circle to the edge of the semicircle.

**Step 2.** Square the radius. Multiply the radius by itself.

**Step 3.** Multiply the squared radius by pi. Use the value of pi as 3.14159.

**Step 4.** Divide the result by 2 to get the area of the semicircle.

**For example,** let’s say the radius of the semicircle is 5 cm. To find the area of the semicircle, we can use the formula:

Area of a semicircle = (π * r²)/2

= (3.14159 * 5²)/2

= (3.14159 * 25)/2

= 39.27 cm²

Therefore, the area of the semicircle is 39.27 square centimeters.

## Area of Semicircle Formula

The formula for the area of a semicircle is:

where:

A = area of the semicircle

r = radius of the semicircle

π ≈ 3.14159 (pi, a mathematical constant representing the ratio of the circumference of a circle to its diameter)