# Formula for the Area of a Semicircle

A semicircle is a half of a circle, and calculating its area involves a specific formula that’s derived from the formula for the area of a circle. Let’s delve into this formula and understand how it works.

**The Formula:**

The formula for calculating the area of a semicircle is:

Area of Semicircle=21×*π*×*r*2

Where:

*π*(Pi) is a mathematical constant approximately equal to 3.14159.*r*represents the radius of the semicircle.

**Understanding the Formula:**

The formula for the area of a semicircle is derived from the formula for the area of a circle, which is*π*×*r*2. Since a semicircle is half of a circle, we need to divide the area of a circle by 2 to get the area of a semicircle.

By substituting the values of (\pi) and (r) into the formula, we get the area of the semicircle. Remember that the radius (r) is measured from the center of the circle to the outer edge of the semicircle.

**Example Calculation:**

Let’s work through an example to illustrate the formula. Suppose we have a semicircle with a radius of 8 units.

**Using the formula:**

Area of Semicircle=21×*π*×(82)

Area of Semicircle=12×3.14159×64

Area of Semicircle=21×3.14159×64

Area of Semicircle≈100.53096 square units

Area of Semicircle≈100.53096 square units

So, the area of the semicircle with a radius of 8 units is approximately 100.53096 square units.

**Conclusion:**

The formula for the area of a semicircle, (\frac{1}{2} \times \pi \times r^2), provides a straightforward way to calculate the space enclosed by a semicircular shape. This formula is derived from the area formula of a full circle and is a fundamental concept in geometry and mathematics as a whole.