2nd October 2019

14

# What do you call a half circle?

Half a circle called a semi-circle (with or without a hyphen). semicircle noun. a half of a circle or of its circumference. [ODO] Half a sphere (like an igloo) is a hemisphere (which I've not generally seen hyphenated).

Keeping this in consideration, what is the formula for semi circle?

In the case of a circle, the formula for area, A, is A = pi * r^2, where r is the circle's radius. Since we know that a semicircle is half of a circle, we can simply divide that equation by two to calculate the area of a semicircle. So, the formula for the area of a semicircle is A = pi * r^2/2.

What is the measure of an angle inscribed in a semicircle?

Proof: The intercepted arc for an angle inscribed in a semi-circle is 180 degrees. Therefore the measure of the angle must be half of 180, or 90 degrees. In other words, the angle is a right angle.

How do you work out semi circle area?

Steps
1. Find the radius of the semi-circle. You'll need the radius to find the area of the semi-circle.
2. Find the area of the full circle and divide it by two. The formula for finding the area of a full circle is πr2, where "r" represents the radius of the circle.