Triangle Calculator Area and Perimeter

How to Use This Calculator

1. Enter the lengths of the three sides of your triangle in the input fields (Side A, Side B, and Side C).
2. Click the "Calculate" button to compute the area and perimeter.
3. The calculator will display the perimeter (sum of all sides) and area using Heron's formula.
4. The calculator will also indicate whether your triangle is equilateral, isosceles, or scalene.

Understanding the Formulas

Perimeter

The perimeter of a triangle is simply the sum of all its sides:

Perimeter = a + b + c

Area (Heron's Formula)

Heron's formula is used to calculate the area of a triangle when you know the lengths of all three sides:

s = (a + b + c)/2

Area = √(s(s-a)(s-b)(s-c))

Where 's' is the semi-perimeter of the triangle.

Triangle Types

• Equilateral Triangle: All three sides are equal in length.
• Isosceles Triangle: At least two sides are equal in length.
• Scalene Triangle: All three sides have different lengths.

Important Notes

For a valid triangle, the following triangle inequality theorem must be satisfied:

• The sum of any two sides must be greater than the third side.
• a + b > c
• a + c > b
• b + c > a