Geometry Area Calculator

Calculate areas of common shapes such as circles, rectangles, triangles, trapezoids, and ellipses.

Select Shape
Circle Area Calculation

Area Formula Reference

  • Circle: S = πr²
  • Rectangle: S = a × b
  • Triangle: S = ½ah
  • Trapezoid: S = ½(a + b)h
  • Ellipse: S = πab
  • Parallelogram: S = ah
  • Sector: S = πr²θ/360
  • Rhombus: S = ½d₁d₂

Usage Instructions

Features

Calculate areas of 8 common geometric shapes including circles, rectangles, triangles, trapezoids, ellipses, parallelograms, sectors, and rhombuses online, with formulas shown alongside for learning and verification.

Steps

Click a shape in the "Select Shape" area → Enter the required parameters (such as radius, base, height) → The area and formula will be displayed automatically below.

Notes

All calculations run locally in your browser with no data uploaded; inputs must be positive numbers, sector angle range is 0-360 degrees; results keep high-precision decimals and will not display when parameters are incomplete or invalid.