Area Calculator
Calculate the area of common geometric shapes including rectangles, circles, triangles, and trapezoids.
About this Calculator
Calculate the area of common geometric shapes including rectangles, circles, triangles, and trapezoids.
Formula & Calculations
Formula
Rectangle: A = l·w; Circle: A = πr²; Triangle: A = ½bh; Trapezoid: A = ½(b₁+b₂)hWhere:
- A=Area of the shape in square units
- l=Length (rectangle)
- w=Width (rectangle)
- r=Radius (circle)
- b=Base (triangle)
- h=Height (triangle, trapezoid)
- b₁, b₂=Top and bottom bases (trapezoid)
Assumptions
- All measurements use consistent units; output area uses the square of the input unit.
- Circle area uses π ≈ 3.1415926535.
Calculation Examples
Example 1
Inputs:Shape: Rectangle, Length: 8, Width: 5
Result:40 square units
8 × 5 = 40 square units.
Example 2
Inputs:Shape: Circle, Radius: 7
Result:153.94 square units
π × 7² = π × 49 ≈ 153.94 square units.
Frequently Asked Questions
What units should I use?
The calculator is unit-agnostic. Enter dimensions in the same unit (e.g., all in feet or all in meters), and the result will be in that unit squared.
How do I calculate the area of an irregular shape?
Break the irregular shape into regular shapes (rectangles, triangles, circles), calculate each area separately, and sum the results.