Area of an Ellipse
(KS3, Year 7)
In this formula, a is the semi-minor axis and b is the semi-major axis. The image below shows what we mean by the semi-minor and semi-major axis:
How to Find the Area of an Ellipse
Finding the area of an ellipse is easy.Question
What is the area of an ellipse with a semi-minor axis of 3 cm and a semi-major axis of 5 cm, as shown below?Step-by-Step:
1
Start with the formula:
Area = πab
Don't forget: π is pi (≈ 3.14) and πab = π × a × b
2
Substitute the semi-minor and semi-major axis into the formula. In our example, a = 3 and b = 5.
Area = π × 3 × 5 = 47.1 cm2
Answer:
The area of the ellipse with a semi-minor axis of 3 cm and a semi-major axis of 5 cm is 47.1 cm2."Find the Area" Widget
Here is a widget to help you learn the formulas to find the areas of different shapes.- Click on the shape you're learning about.
- Click on the pad to start.
- Follow the instructions in the bottom-left corner.
- On the last click, the formula, workings, and answer will appear in the yellow box.
- Enjoy!
What Is an Ellipse?
An ellipse is a squashed circle. It is symmetrical about its longest axis (called the major axis) and its shortest axis (called the minor axis).Half of the major axis is the semi-major axis. Half of the minor axis is the semi-minor axis.
Worksheet
This test is printable and sendable