Step By Step Lessons to Find the Area of a Circle
If you want to learn or teach how to find the area of a circle when its radius is given then visit this page. Free pdf worksheets and lessons to print.....
Visit this page if you want to print lessons and worksheets on how to find the area of a circle when you know its diameter.
Yes! you can find the area of any circle when its circumference is given. So if you know the circumference of a circle you can find its area easily......
This page explains how to find the radius of given circle if you know its area. You can print cool lessons and worksheets to practice the concept....
Steps towards learning how to find the area of any circle:
Before learning how to find the area of a circle let's understand the concept of surface area or simply area.
Area is the surface enclosed in the closed boundaries and these boundaries can be square in shape, rectangular or circular or any other shape.
The key to find the area of any shape is the square shape with a unit length (or unit squares). To find the area any other kind of shape that shape is filled with these unit squares and then these squares are counted to find the area of the shape.
For example; consider there is a rectangle with a length of 10 cm and width of 5 cm as shown below:
Now the above rectangle can be filled with 50 unit squares of side length 1 cm. So the area of the rectangle will be 50 centimetre squares.
Similarly area of the circle can be found by drawing small unit squares inside the circle, but the problem will be the circular boundaries of this shape. As a result we can't fit exact number of squares inside a circle. See the picture given below:
From the above figure it is clear that we can't find the exact area of a circle because we can't fit exact number of squares inside a circle. But still we can give a good estimate of the area of the above circle by counting the full squares and half squares inside it.
Hence we need a consistent and easy method to find the area of a circle. So the mathematicians develop a formula to find the area of any given circle.
You need to know about the diameter of a circle then its radius and finally a constant pi.
The longest chord of the circle is called its diameter or any chord of the circle going through its centre is called the diameter.
Half the length of the diameter is called the radius.
The ratio of circumference of a circle to its diameter is always constant and is called pi. Its value is 3.14 (To 2 decimal places).
Lessons and worksheets on how to find the area of a circle
Print the following area of circle worksheet ex planing how to find the area of a circle when its radius (r) is given.
(click on worksheets to print it)
Print the following worksheet to teach kids about how to find the circle area when its diameter is given.
More areas of circles worksheets are given below: