How to use the Area Calculator
The area calculator finds the area of common 2D shapes.
What you need to enter
- Shape
- a
- b
- c (trapezoid height)
The formula
Rectangle ab; triangle ½bh; circle πr²; trapezoid ½(a + b)h; ellipse πab.
Worked example
Using the default values in the calculator:
- Shape: Rectangle (a × b)
- a: 5
- b: 4
- c (trapezoid height): 3
| Area | 20 |
Tips for better results
- Use the same unit for all sides.
- Area is in square units.
Common mistakes to avoid
- Using diameter for radius.
- Mixing units.