What is Heron's formula?

When you know all three sides (a, b, c): s = (a+b+c)/2, then A = √(s(s-a)(s-b)(s-c)).

How do I find area with two sides and an angle?

A = ½ × a × b × sin(C), where C is the included angle between sides a and b.

Can a triangle have the same area with different dimensions?

Yes! A 4×5 triangle has the same area as a 2×10 triangle (both = 10 sq units).

How to Calculate the Area of a Triangle

There are multiple ways to calculate the area of a triangle depending on what information you have — base and height, three sides, or two sides with an angle.

Triangle Area (Base-Height)

A = ½ × base × height

Where:

A = Area of the triangle
b = Base length
h = Height (perpendicular to base)

Step-by-Step:

1
Identify base and height
The height must be perpendicular to the chosen base.
2
Multiply
Multiply base by height.
3
Divide by 2
Divide the product by 2.

Worked Examples:

Simple triangle

Base: 10 cmHeight: 6 cm

Result: 30 sq cm

A = ½ × 10 × 6 = 30 sq cm