Area- Circles

Understanding Circles and Their Areas

Circle Parameters

A circle is a perfectly round shape where all points on the edge are the same distance from its centre.
The radius is the line segment from the centre to any point on the edge of the circle.
The diameter is a line passing through the centre and reaching both edges of the circle, double the length of the radius.
The circumference is the total length around the circle.

Area of a Circle

The area is the amount of space inside the circle.
The formula to calculate the area of a circle is A = πr². A stands for area, r represents the radius of the circle.
This formula is saying that the area of the circle is equal to pi (approximated as 3.14159265) multiplied by the radius squared.
To square a number means to multiply it by itself.
So to find the area, you first need to find the radius, square it (multiply it by itself), and then multiply that by pi.
If the diameter is given, remember to halve it to find the radius before using the formula.

Practical Applications

Recognising circular shapes in the environment and understanding the method to calculate their areas can assist in solving real-world geometric problems.
For example, calculating the area of a circular garden to figure out how many packages of seeds to buy or computing the space a circular table occupies in a room.

Understanding the properties of a circle, its radius, circumference, area, and the relationships between them, is an essential skill you’ll often use in solving geometry problems. Do regular exercises and problems involving circles to fully master the concept.