About Triangle Calculator

Calculate triangle perimeter and area from three sides.

How to Use

Calculate triangle perimeter and area from three sides. Enter the Side A, Side B, and Side C values and review the Perimeter, Area, and Status outputs after you calculate.

  1. Open the calculator : Use Triangle Calculator from the Math category.
  2. Check the inputs : Review the required values and any optional settings.
  3. Read the formula : Use the formula and notes below to understand how the result is produced.

Common Questions

What formula does the Triangle Calculator use?

Uses Heron formula when sides form a valid triangle.

Inputs

  • Side A
  • Side B
  • Side C

Outputs

  • Perimeter
  • Area
  • Status

Formula

Uses Heron formula when sides form a valid triangle.

Triangle Calculator

Calculate triangle perimeter and area from three sides.