Area calculator
Find area in cm² for a triangle, rectangle, trapezoid or circle using the relevant dimensions.
Formula
Rectangle: ab; triangle: ah/2; trapezoid: (a+b)h/2; circle: πa². Lengths in cm.
Length / base a / radius: 6 cm · Width / second base b: 4 cm · Perpendicular height h: 5 cm · Area ≈ (6 cm × 0.01 m/cm)×(5 cm × 0.01 m/cm)÷2×10000
How to use
- Choose the plane shape.
- Enter dimensions and units.
- Read the area in cm².
Examples
- A triangle with base 6 cm and height 5 cm has area 15 cm².
Frequently asked questions
Which dimensions are needed?
Rectangle: a, b. Triangle: base a, height h. Trapezoid: parallel bases a, b and height h. Circle: radius a.
What does height mean?
The perpendicular distance, not a sloping edge.
What happens to unused dimensions?
Leave their positive defaults; they do not change the selected result.
Sources
Updated: