Triangle Calculator: Find Area, Perimeter, and Angles
Calculate triangle properties including area, perimeter, and angles using our free online triangle calculator. Input three sides or base and height for accurate results.
Category: Math
Triangle Calculator
Calculate the area, perimeter, and angles of a triangle using different methods.
Frequently Asked Questions
How do you calculate the area of a triangle?
There are multiple ways to calculate a triangle's area. The most common is the formula Area = (base × height) ÷ 2. For triangles where you know all three sides, you can use Heron's formula: Area = √(s(s-a)(s-b)(s-c)) where s = (a+b+c)/2.
What is Heron's formula for triangle area?
Heron's formula calculates the area of a triangle when all three sides are known. First, find the semi-perimeter s = (a+b+c)/2, where a, b, and c are the sides. Then calculate Area = √(s(s-a)(s-b)(s-c)).
How do you calculate the angles of a triangle?
If you know all three sides of a triangle, you can calculate the angles using the Law of Cosines. For angle A: cos(A) = (b² + c² - a²)/(2bc), where a is the side opposite to angle A.
How do you check if three sides can form a triangle?
Three sides can form a triangle only if they satisfy the triangle inequality theorem: the sum of the lengths of any two sides must be greater than the length of the remaining side. For sides a, b, and c, this means a + b > c, a + c > b, and b + c > a.