Use this geometry calculation when the shape, dimensions, coordinate system, and units match the stated ideal Euclidean model.

Side A

Required number input.

Side B

Required number input.

Side C

Required number input.

Sum three side lengths of a triangle. The tool evaluates the supplied inputs together and returns the named outputs below; it does not infer omitted operating conditions or change the units shown.^[1]

Perimeter

The resulting perimeter returned as a number.

• The result assumes exact idealized geometry. Measurement uncertainty, rounded inputs, nonplanarity, self-intersection, thickness, curved coordinate systems, and ambiguous dimension definitions are not automatically represented.
• Use finite inputs in the displayed units and preserve more precision than the final presentation requires. Independently verify safety-critical, financial, compliance, or production decisions.

Sketch and label the dimensions, verify unit consistency, and use coordinate or CAD methods for irregular measured shapes.

• Pythagorean Theorem Calculator

  Calculate a missing side of a right triangle from two known sides.

• Regular Hexagon Perimeter Calculator

  Calculate the perimeter of a regular hexagon as six times its side length.

• Right Triangle Calculator

  Calculate a right triangle's hypotenuse, area, and perimeter.