# How to Find the Area of a Triangle

## Finding the Area of a Triangle

The area of a triangle is found using the formula:

In this formula, **b** is the length of the base of the triangle and **h** is the height of the triangle. The image below shows what we mean by the lengths of the bases and the height:

## How to Find the Area of a Triangle

### Question

What is the area of a triangle with a base of 5 cm and a height of 3 cm, as shown below?

### Step-by-Step:

# 1

Start with the formula:

Area = ½(b_{1} + b_{2})h

**Don't forget:** ½bh = ½ × b × h

# 2

Substitute the length of the base and the height into the formula. In our example, b = 5 and h = 3.

Area = ½ × 5 × 3 = 7.5 cm^{2}

**Don't forget:** ½ × a number = 0.5 × a number = a number ÷ 2.

### Answer:

The area of the triangle with a base of 5 cm and a height of 3 cm is 7.5 cm^{2}.

## How to Find the Area of a Triangle Using Trigonometry

The area of a triangle can also be found using trigonometry.

The area is found using the formula:

In the formula, **a** and **b** are lengths of two sides of the triangle and **C** is the angle between them. The image below shows what we mean by the two sides and the angle between them:

Read more about how to find the area of a triangle using trigonometry