# The Circle | What is Circle Definition | Features and Formula of Circle

Circle we study of the Circle. Circle is the basic 2D Geometrical plane shape, which has Circumference, Radius. In this chapter we read about Definition of Circle, Circle Circumference, Circle Radius, Diameter of Circle and other different part of circle with Circle important Formula. We also will know about Circle Formula. So let’s start.

# The Circle Circle Definition

The set of all those points in the same plane, in which each point is located at a certain distance from a point, called Circle.
Different Parts of Circle
A Circle have many parts like Circle Center, Circumference, Radius, Diameter, Chord, Arc, Sector of Circle etc.

The distance from the circle center to circumference is called the radius of the circle.
The line segment passing through the center of the circle with its two ends located on the circumference, is called the diameter of the Circle.
Here AB is a diameter of Circle, There are many diameter in a Circle. We show diameter with d.
d = 2r

## Center of Circle

A point which distance is equal from the circumference, called Center of Circle.

## Circumference of Circle

The distance traveled along an entire circle along the circle is called the circumference of the circle.
Here is circumference all around the center of Circle.

## Chord of The Circle

The line segment joining any two points on the circle is called the chord of the circle.
Diameter are also a chord and diameter is the largest chord of the Circle.

## Arc of Circle

The part of the circle between the two points on the circle circumference is called the arc of the circle.
and AYB is Long Arc.

## Sector of Circle

The area surrounded by an arc formed from two radii and their last points is called the sector of the circle.

## Segment of Circle

A part of a circle that is bounded between a chord and an arc is, called Segment of Circle.
AYB is long segment.

## Important Formula of Circle

Here Above in Online tutoring class “Tutor Dose” we read about various parts of Circle and their definition. Now we read about Circle Formula.

### Area of Circle

Area of Circle = Πr2

### Circumference of Circle

Circumference of Circle = 2Πr

### Diameter of Circle

Diameter of Circle = 2r

Radius of Circle = $$\displaystyle \frac{{\sqrt{{Area}}}}{\pi }$$
here A = Area of Circle

Radius of Circle = $$\displaystyle \frac{C}{{2\pi }}$$
(here C = Circumference of circle)

### Area bounded by two concentric circles

Area bounded by two concentric circles = $$\displaystyle \pi \left( {r_{1}^{2}-r_{2}^{2}} \right)$$
(where r1 & r2 is radius of both circle)

### Length of Circle Arc

Length of Circle Arc = $$\displaystyle \frac{\theta }{{360{}^\circ }}\times 2\pi r$$
Theta = Angle on Center of Circle

### Area of Small Sector of Circle

Area of Small Sector of Circle = $$\displaystyle \frac{1}{2}\times {{r}^{2}}\times \theta$$ (When radius r and sector of a circle angle are given)
theta = Angle of Sector

### Area of Sector of a Circle

Area of Sector of a Circle = $$\displaystyle \frac{1}{2}\times L\times r$$
L = Arc Length
(When radius r and arc length L are given)

### Area of Small Segment

Area of Small Segment = $$\displaystyle \frac{{\pi {{r}^{2}}\theta }}{{360}}-\frac{1}{2}{{r}^{2}}\sin \theta$$

### Some Important Questions on Circle

Q.1 A circle diameter is 136 cm, find the area of circle ?
Solution – Diameter of Circle = 136 cm
Radius of Circle = $$\displaystyle \frac{{136}}{2}$$ = 68 cm
Area of Circle = $$\displaystyle \pi {{r}^{2}}$$
A = $$\displaystyle \frac{{22}}{7}\times 68\times 68$$
A = 101728/7
A = 14532.57 square cm Answer

### One thought on “The Circle | What is Circle Definition | Features and Formula of Circle”

• October 17, 2021 at 8:20 pm