#### Equation of a circle example

## What is the equation for a circle?

First you need to know that the equation for a circle is (x-a)^2 + (y-b)^2 = r^2 where the center is at point (a,b) and the radius is r.

## What is the function for a circle?

A circle is a set of points in the plane. A function is a mapping from one set to another, so they’re completely different kinds of things, and a circle cannot be a function. What you presumably meant to ask is whether the circle is the graph of some function.

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

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

## How do you find the center and radius of a circle with an equation?

The center-radius form of the circle equation is in the format (x – h)^{2} + (y – k)^{2} = r^{2}, with the center being at the point (h, k) and the radius being “r”.

## What’s a standard form?

Standard form is a way of writing down very large or very small numbers easily. So 4000 can be written as 4 × 10³ . This idea can be used to write even larger numbers down easily in standard form. Small numbers can also be written in standard form.

## How do you plot a circle?

follow these steps:Realize that the circle is centered at the origin (no h and v) and place this point there.Calculate the radius by solving for r. Set r-squared = 16. Plot the radius points on the coordinate plane. Connect the dots to graph the circle using a smooth, round curve.

## What is the radius of a circle?

The Radius is the distance from the center outwards. The Diameter goes straight across the circle, through the center. The Circumference is the distance once around the circle.

## How do you find area?

To find the area of a rectangle, multiply its height by its width. For a square you only need to find the length of one of the sides (as each side is the same length) and then multiply this by itself to find the area.

## Why is the area of a circle πr2?

The height becomes equal to the radius, while the length is half of the circumference (C = 2πR) which now finds itself running along the top and bottom. As the number of triangles “approaches infinity” the circle can be taken apart and rearranged to fit almost perfectly into an “R by πR” box with an area of πR^{2}.