△ Area of Triangle Calculator

Triangle Area

Triangle Area Formulas

There are multiple ways to calculate a triangle's area depending on what measurements you know.

Base & Height: Area = (1/2) × base × height
Heron's: s = (a+b+c)/2, Area = √(s(s−a)(s−b)(s−c))
SAS: Area = (1/2) × a × b × sin(C)

Types of Triangles

  • Right triangle: One 90° angle; base and height are two of its legs.
  • Equilateral: All 3 sides equal. Area = (√3/4) × side².
  • Isosceles: Two equal sides.
  • Scalene: All sides different — use Heron's formula.

Frequently Asked Questions

How do you find the area of a triangle with base 10 and height 6? ▼
Area = (1/2) × 10 × 6 = 30 square units.
What is Heron's formula? ▼
Heron's formula calculates area using all three sides: s = (a+b+c)/2 (semi-perimeter), Area = √(s×(s−a)×(s−b)×(s−c)). Useful when height is not given.
What is the area of an equilateral triangle with side 6? ▼
Area = (√3/4) × 6² = (√3/4) × 36 = 9√3 ≈ 15.59 square units.