# 11.8.4. Heron's Formula

Determine the area of the figure below to the nearest 3 decimal places using Heron's formula.

- A
- B
- C
- D

### Example

Determine the area of the figure below to the nearest 3 decimal places using Heron's formula.

### Solution

Heron's formula for the area of a triangle with sides

To find the area of this shape, we calculate the area of the triangle and the rectangle. Firstly, we apply Heron's formula to calculate the area of the triangle. We start by finding the semi-perimeter

From this, we can calculate the area of the triangle.

The total area of the shape is the sum of the area of the triangle and the area of the rectangle. Hence,