A circle is a basic 2D shape in geometry. It is a closed curve made up of all points equidistant from a fixed center point with no corners and edges.  We see circles around us as wheels, coins, and clock faces.

Website - Gumroad 9 To 11 CTA Banner

Parts of a circle

Center : The fixed point in the middle of the circle.

Radius : The distance from the center to any point on the circle.

Diameter : The distance across the circle passing through the center (twice the radius).

Circumference : The distance around the circle.

Chord : A line segment that connects any two points on the circle.

Arc : A part of the circumference is called the arc of the circle.

Regions in a circle

As a circle is a closed figure, it has the following three regions : 

Interior Region : 

The interior region is the entire region inside a circle and points lying in this interior region are called interior points. 

The Exterior Region : 

The exterior region is the entire region outside a circle and points lying in this exterior region are called exterior points. 

On the Circle : 

Points lying on the boundary are said to be on the circle.

Drawing Circles

We use a compass and pencil to draw a circle by following steps : 

  • Place the sharp end of the compass at the center point and the pencil end on the paper.
  • Adjust the compass width to the desired radius length.
  • Rotate the compass around the center point, creating a circle.

Properties of a circle :

  • All points on the circle are equidistant from the center.
  • The radius of a circle is always half the length of its diameter.
  • The diameter is the longest chord in a circle, and it divides it into two equal halves called semicircles.
  • We calculate the circumference of a circle by using the formula: C = 2πr or C = πd (where π is approximately 3.14).

Points to ponder about a circle : 

  • A circle is a curved shape without any edges.
  • A circle’s complete arc is 360 degrees in length.
  • The diameter is the longest chord of the circle.
  • The result of dividing the diameter’s length by its circumference is 3.141592654, or (Pi), which is a mathematical constant.
Uncle Math 9 to 11 Years App Banner
Uncle Math 9 to 11 Years App Banner


Teaching circles with kid-friendly, clear, and easy-to-understand posters from Uncle Math School by Fun2Do Labs :


Ignite kids’ curiosity with engaging stories for role play and skits, making the learning of this concept an exciting and effective experience. Teaching  circles through stories from Uncle Math School by Fun2Do Labs :

Text Of The Stories


Learning circles can be made enjoyable by incorporating the following interactive games and activities.

  1. Play “Guess the Object” where children describe circular objects and others have to guess.
  2. Measure the radius and diameter of circular objects using a ruler or measuring tape in the surroundings.
  3. Draw and label circles with the given measurements (radius and diameter).


Help your kids practise circles with interesting and engaging fun worksheets and solutions from Uncle Math by Fun2Do Labs.

Worksheet 683 : Parts Of Circle
Solution 683 : Parts Of Circle
Worksheet 684 : Circumference Of Circle
Solution 684 : Circumference Of Circle
Worksheet 685 : Circumference Of Circle
Solution 685 : Circumference Of Circle
Worksheet 686 : Radius And Diameter
Solution 686 : Radius And Diameter

Explore Related Guides :