To calculate the area of a semicircle, first find the radius. The radius is half the diameter. Then, square the radius by multiplying it by itself. Next, multiply the squared radius by π*π* (about 3.14). Finally, divide the result by 2 since a semicircle is half of a full circle. This will give you the area of the semicircle.

**Formula :**

** $A=\pi \times {r}^{2}\times \left(\frac{\theta}{360}\right)$**

Variable | Description |
---|---|

A | Area of the semicircle |

r | Radius of the semicircle |

π | Pi (approximately 3.14159) |

θ | Angle of the semicircle (180° for a semicircle) |

**Solved Calculation**

**Problem:** What is the area of a semicircle with a radius of 11 units?

Step | Calculation |
---|---|

1 | Use the formula $A=\frac{\pi \times {r}^{2}}{2}$ |

2 | Substitute the radius $r=11$ into the formula |

3 | $A=\frac{3.14159\times 1{1}^{2}}{2}$ |

4 | $A=\frac{3.14159\times 121}{2}$ |

5 | $A=\frac{380.132}{2}$ |

6 | $A=190.07\text{\hspace{0.17em}}\text{square units}$ |

**What is Area of Semi Circle ?**

The area of a semicircle is half of the area of a full circle. If you know the diameter instead of the radius, you can first divide the diameter by two to find the radius, then apply the formula.

Whether you’re working with measurements in inches, centimeters, or other units, this tool helps you quickly and accurately find the area for any semicircle. It’s particularly useful for construction, landscaping, or design projects where precise area measurements are essential.