How Many Sides Does a Circle Have

Introduction

A circle is a round plane figure whose circumference has points equidistant from a fixed point called the centre. All the lines passing through the circle form the line of reflection symmetry. A circle is a two-dimensional figure hurdled with one single curved line so that all the straight lines that are drawn from a certain point within the circle to the bounding line are equal. A circle does not have any sides because it is not made up of any lines and also does not have any angles.

Parts of a circle

• Circumference - the border of the circle is called the circumference.

• Tangent - a line that taps the circumference of the circle at one point is called a tangent.

• Radius - A line that starts from the centre of the circle and ends at the circumference of the circle is called the radius and it is designated as “R” or “r”.

• Diameter - a line that proceeds through the centre of the circle and taps the two points on the circumference is known as the diameter. It is denoted by “D” or “d”.

• Chord - an unbending line that joins any two points on the circumference of the circle is known as the chord.

• Arc - an arc is a fragment of the circumference. The larger arc is called the major arc and the smaller arc is called the minor arc.

• Sector - the sector is a part of the circle hurdled by two radii and the arc of a circle is included.

• Secant - a line that cuts the circle at two faraway points is called a secant.

Properties of a circle

• The circles are said to be concordant if they have similar radii.

• The diameter of a circle is said to be the longest chord of a circle.

• A circle can circumscribe other shapes like a triangle, square, trapezium, or rectangle.

• A radius that is drawn perpendicular to a chord intersects the chord.

• The distance between the longest chord of the circle which is the diameter and the centre of the circle is zero.

• The perpendicular distance from the centre of a circle reduces when the length of the chord is increased.

• If the tangents of a circle are put at the end of the diameter, they will be parallel to each other.

• An isosceles triangle is made when the radii of a circle join the ends of a chord to the centre of a circle.

• Equal chords of a circle couple equal angles at the centre.

Formulas of a Circle

The area of a circle can be denoted by

A = \pi r^{2}

The circumference of a circle is denoted as

2\pi r

Or the circumference of a circle formula can also be denoted as

\pi d

Diameter = 2\times Radius

(where “r” is denoted as the radius of the circle).

Facts about Circle

A circle is a two-dimensional figure that is formed by all those points that are equidistant from a centre point. The area that is enclosed within a circle is known as the disc. A circle is the most symmetric figure because every line that passes through the centre is a line of reflection of symmetry. The circle has a rotation symmetry for every single angle around its centre. The full arc of a circle will always measure 360 degrees. A circle is a unique type of ellipse in which the two foci are in the same position and the eccentricity is zero.

Notes

The most important part of a circle is its centre. Circles are important because they are symbolically still important these days - they are often used to represent harmony and unification. Circles are the best shape because they are not like other geometric bodies, they do not have angles and this makes a circle look softer and more gentle than other shapes.