Area Calculator
Area and perimeter of common shapesRuns locally · nothing uploaded
S = a²，C = 4a
- Area25 cm²
- Perimeter20 cm
- Diagonal7.071068 cm
Also works as:triangle area calculatorcircle area calculatortrapezoid areaheron's formula calculator
How to use
- 1Pick a shape.
- 2Enter its dimensions and unit.
- 3Read the area and perimeter.
FAQ
How do I find a triangle's area from three sides?
Heron's formula: s = (a+b+c)/2, area = √[s(s−a)(s−b)(s−c)]. A 3-4-5 triangle has area 6.
What is the area of a circle?
πr². A circle of radius 3 has area ≈ 28.27.