# Maths formulas for class 9 chapter- Circles Formula

## Class 9 chapter- Circles Formula

It is a collection of points whose distance from a fixed point always remains constant. The fixed point is called the center of the circle and the fixed distance is called the radius of the circle. The length of the complete circle is called its circumference.

Elements of a circle

Let P and Q are two points on the circumference of the circle.

•  Chord- Line Segment (PQ) joining any two points on a circle is called chord.

Chord that passes through the center of the circle is called the diameter.

1. Diameter is the longest chord.
2. All diameters have the same length, which is equal to two times the radius.
• Arc- A piece of a circle between two points is called Arc. The longer one is called the major arc and the shorter one is called the minor arc.
1. When P and Q are ends of a diameter then both arcs are equal and each is called a semicircle.
• Segment- The region between a chord and either of its arcs is called a segment of the circle. The larger region is called as major segment and the smaller region is called as minor segment.

• 4. Sector- The region between an arc and the two radii, joining the center to the end points of the arc is called a section. Larger one is called as major sector and the smaller one as minor sector.
1. When two arcs are equal, that is, each is a semicircle, then both segments and both sectors become the same and each is known as a semicircular region.

• 5. Tangent- A line which intersects the circle at exactly one point is called a tangent.
1. At a point of a circle there is one and only one tangent.
2. From an external point of a circle two tangents can be drawn to the circle.

• Secant- A line which intersects the circle at two distinct points is called a Secant.

NCERT Solutions are very helpful to score good marks in Class 9 Maths do solve questions from text book with the help of NCERT Solutions for class 9 Maths prepared by Academic team of  Physics Wallah.  If any students need to take the online test to check their concepts or undertstanding then they can visit Quiz for Circles.

To download the pdf of maths formulas for class 9 chapter- Circles click the Link given below