#### Equation of a half circle

## What is the function of a half circle?

A semicircle can be used to construct the arithmetic and geometric means of two lengths using straight-edge and compass. For a semicircle with a diameter of a + b, the length of its radius is the arithmetic mean of a and b (since the radius is half of the diameter).

## What is the formula of diameter of semicircle?

The diameter, like in a normal circle, is just twice the radius. If given the perimeter: The perimeter of a semicircle will be one half the circumference of its original circle, πd , plus its diameter d . Note: by no means should you commit to memorizing the area or perimeter formulas I’ve derived here.

## How do you find the volume of a half circle formula?

To find the area of a semicircle, you need to know the diameter, which is the distance across the semicircle. If you have half a sphere, you can find the volume by finding the area of the whole sphere and dividing by 2.

## What shape is a half circle?

A closed shape consisting of half a circle and a diameter of that circle*. A semicircle is a half circle, formed by cutting a whole circle along a diameter line, as shown above. Any diameter of a circle cuts it into two equal semicircles. * An alternative definition is that it is an open arc.

## How do I calculate the area of a circle?

The area of a circle is pi times the radius squared (A = π r²).

## What is πr2?

The area of a circle is given by the formula A=πr2. Where the area A is given by the blue shaded region, r is the radius of the circle, and π≈3.14. Arectangle= base × height =πr×r Here, the area of rectangle is exactly equal to the area of circle, so: Acircle=πr2.

## What does πr2 mean?

Example The Area A of a circle with radius r is given by the formula A = πr2. In this formula π ≈ 3.1416 is a number, and A and r are variables or unknowns. A is called the subject of the formula. The subject of a formula is the variable or unknown we are interested in.

## What is the formula of volume?

Whereas the basic formula for the area of a rectangular shape is length × width, the basic formula for volume is length × width × height.

## What is the volume of a half circle?

The volume of a circular cylinder is π r^{2} h where r is the radius and h is the height. If the cylinder is on its side then the height h is the length so the volume of a semicircular trough is 1/2 π r^{2} h.

## What is a 1/4 circle called?

Quarter of a circle is called a Quadrant. Half a circle is called a Semicircle.

## What is a quarter circle called?

A sector can be any size, however a sector that is half a circle (180°) is called a semicircle, while a quarter circle sector (90°) is called a quadrant.