Geometry Calculator
Area and perimeter for a circle, rectangle or triangle.
What is a geometry calculator?
A geometry calculator finds the area and perimeter of a circle, rectangle or triangle. Example: a circle with radius 5 has area about 78.54 and circumference about 31.42.
How to use it
Choose a shape, enter its measurements, then tap Calculate.
Formulas
Circle: Area = πr², Circumference = 2πr. Rectangle: Area = length × width, Perimeter = 2(length + width). Triangle: Area = ½ × base × height, Perimeter = side 1 + side 2 + side 3.
Example
A circle with radius 5 has area π × 5² = about 78.54 and circumference 2 × π × 5 = about 31.42.
Frequently Asked Questions
What is the area of a circle with radius 5?
About 78.54.
What is the area of a rectangle 6 by 4?
24.
What is the area of a triangle with base 6 and height 4?
12.
More calculators: Math Tools and All Tools.