📐 Triangle Calculator
Calculate area, perimeter, angles, and side lengths for all types of triangles.
Triangle Calculator Features
📏 All Triangle Types
Calculate properties for right triangles, isosceles, equilateral, scalene, acute, and obtuse triangles using various input combinations.
🔢 Multiple Methods
Use different calculation methods: three sides (SSS), two sides and angle (SAS), two angles and side (ASA), or right triangle properties.
📐 Visual Display
See your triangle drawn to scale with labeled sides and angles. Understand triangle properties through visual representation.
Triangle Calculator FAQ
What information do I need to calculate a triangle?
You need at least 3 pieces of information: either 3 sides, 2 sides and 1 angle, or 2 angles and 1 side. For right triangles, you only need 2 pieces of information.
What's the difference between SSS, SAS, and ASA?
SSS = three sides known, SAS = two sides and included angle known, ASA = two angles and included side known. Each method uses different formulas to solve the triangle.
How is triangle area calculated?
Area can be calculated using Heron's formula (with three sides), base × height ÷ 2, or ½ab sin(C) where a and b are sides and C is the included angle.
What makes a valid triangle?
The triangle inequality theorem: the sum of any two sides must be greater than the third side. Also, the sum of all angles must equal 180°.