Unravelling The Enigma Calculating The Area of a Triangle

how to calculate area of a triangle


The triangle, an ancient and fundamental geometric shape, continues to be a cornerstone of mathematical principles. Whether we are designing structures or exploring the cosmos, understanding how to calculate the area of a triangle is paramount. In this article, we will embark on a journey to unravel the enigma behind this simple yet intriguing concept. We will explore the different methods of calculating triangle area, from the basic formula to more specialised techniques. By the end of this article, you will have gained a clear understanding of the beauty and versatility hidden within the triangular realm.

The Foundation of Triangle Area 

At the heart of calculating the area of a triangle lies a straightforward formula: Area = (base × height) / 2. A triangle consists of three sides and three angles, but to use this formula, we need to identify its base and corresponding height. The base is any side of the triangle, while the height is the perpendicular distance from the base to the opposite vertex.

Right-Angled Triangle Area 

For right-angled triangles, those with a 90-degree angle, the calculation becomes even simpler. If we label the two sides that form the right angle as ‘a’ and ‘b’, then the area can be computed as Area = (a × b) / 2. The perpendicular drawn from the right angle to the hypotenuse acts as the height.

Heron’s Formula for Any Triangle 

Heron’s formula is a powerful alternative for calculating the area of any triangle, regardless of whether it is acute, obtuse, or right-angled. Named after the ancient Greek mathematician Hero of Alexandria, this formula involves the use of the triangle’s three sides – ‘a,’ ‘b,’ and ‘c’ – and the semi-perimeter (s) of the triangle, calculated as (a + b + c) / 2. The formula is as follows:

Area = √(s × (s – a) × (s – b) × (s – c))

Heron’s formula might seem complex, but it is extremely useful when the base and height are challenging to determine, or when dealing with irregular triangles.

Area through Trigonometry 

Trigonometry offers another method to calculate the area of a triangle using known side lengths and included angles. If we know two sides ‘a’ and ‘b’ and the included angle ‘θ,’ then the area can be found using the formula: Area = (1/2) × a × b × sin(θ). The sine of the included angle plays a crucial role in this calculation, showcasing the inherent connection between trigonometry and triangle properties.


What is a triangle with 3 different sides?

A scalene triangle can be defined as a triangle whose all three sides have different lengths, and all three angles are of different measures. The angles of a scalene triangle follow the angle sum property and always add up to 180.

What is the area of a 3 sided triangle?

Let ABC be a triangle such that the length of the 3 sides of the triangle is AB = c, BC = a and CA = b. Then, the area of triangle ABC = √[s × (s – a) × (s – b) × (s – c)]. Learn how to find the area of different types of triangles using Heron’s formula.


The journey to uncovering the methods for calculating the area of a triangle has taken us through the foundational formula to the more advanced Heron’s formula and trigonometry. Understanding these techniques equips us to tackle diverse challenges in geometry, architecture, physics, and beyond. Embrace the elegance of triangles, for they are the building blocks of knowledge and innovation.

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