A farmer, Mr Mahlabela, experiences livestock theft and decided to fence his land that is in a rectangular shape. He wants to know how much it can cost him to fence the land. The length of the farm in is 150 metres, the width of the farm is 120 metres and the gate is 5 metres.

The length of the farm is 150 meters and the width is 120 meters.
The formula for the perimeter of a rectangle is $P = 2 \times (\text{length} + \text{width})$.

$$P = 2 \times (150\, \text{m} + 120\, \text{m})$$ $$P = 2 \times (270\, \text{m})$$ $$P = 540\, \text{m}$$

The total perimeter is 540 meters, but a gate of 5 meters will be installed, so that length does not need fencing.

$$\text{Fencing length} = \text{Perimeter} - \text{Gate length}$$ $$\text{Fencing length} = 540\, \text{m} - 5\, \text{m}$$ $$\text{Fencing length} = 535\, \text{m}$$

We assume the cost of fencing is R40 per meter, based on the "40m" visible in the image.

$$\text{Total cost} = \text{Fencing length} \times \text{Cost per meter}$$ $$\text{Total cost} = 535\, \text{m} \times \text{R}40/\text{m}$$ $$\text{Total cost} = \text{R}21400$$

The total cost to fence the land is $\text{R}21400$.