Circle - Geometry

1253
Arnab De
16/07/2020

A circle is a set of point in a plane; those are a given equal distance from a given fixed point in a plane. That fixed point is called the **center** of the circle which is represented by “c”. The distance between any point on the circle and the center is equal. This distance is known as **radius** which is represented by “r”. All the radii in a given circle are **congruent**.

### Circumference

The distance around the circle is called *Circumference*. If we start from point A towards the arrow and stop at the point A. then the total distance is known as Circumference.

### Chord & Diameter

At first, we plot two points on the outer edge of a circle A and B. Then join the point by a line segment AB. This line segment is known as the chord of that circle. i.e. any line segment connects two-point on the outer edge of the circle is called a** chord**.

If a chord passes through the center of the circle i.e. if the given point A, B and C are collinear then that chord known as **diameter** of the circle. Diameter is represented by *d*. Diameter is the *longest chord* in a circle. In a circle *infinite number* of diameter is possible. In diagram P and Q are two points on the outer edges of the circle and C is the center of the circle and P, Q and C are collinear. That is PQ is a diameter of the circle.

*Note*: Every diameter is a chord but every chord is not a diameter.

Here,

### Segment

If we draw a chord in a circle, it clearly divided a circle into two-part each part is known as a segment. i.e. the area enclosed within an arc and a chord of a circle is called a *segment*. If the area of the segments is equals then these are known as *equi-segment*. But those segments are not equal then the smallest segment is known as the *minor segment* and the largest segment is known as the *major segment*.

### Arc

The carved part or the part of the circle between two points is known as an **arc**. Between two points on the circle, we can get two arcs. The smaller arc is known as a *minor arc* and the bigger one is known as a *major arc*.

### Sector

A sector is the area enclose between **two radii** and an **arc**. It is a part of a circle. If we separate a sector from a circle the rest of the part of the circle also creates a sector. Between these two sectors, the smaller one is known as the minor sector and another one is known as the major sector.