Triangle Calculator
Calculate area and perimeter of triangles. Enter values for instant results with step-by-step formulas.
Worked Examples
Example 1: Simple Area
Problem:Base=10, Height=5
Solution:0.5 × 10 × 5
Result:25
Example 2: Perimeter
Problem:Sides 3, 4, 5
Solution:3 + 4 + 5
Result:12
Frequently Asked Questions
What is the sum of angles in a triangle?
The sum of the interior angles of any triangle in a flat plane is always 180 degrees (or π radians).
What is a Right Triangle?
A triangle containing one 90-degree angle. The side opposite the right angle is called the hypotenuse, and the Pythagorean theorem (a² + b² = c²) applies.
What is an Isosceles Triangle?
A triangle with at least two sides of equal length. The angles opposite the equal sides are also equal.
What is a Scalene Triangle?
A triangle where all three sides have different lengths, and all three angles are different.