The area \( A \) of a triangle can be calculated using the formula:
\[ A = \frac{1}{2} \times \text{base} \times \text{height} \]
In this case, the base is 12 m and the height is 5 m. Plugging in these values:
\[ A = \frac{1}{2} \times 12 , \text{m} \times 5 , \text{m} \]
\[ A = \frac{1}{2} \times 60 , \text{m}^2 \]
\[ A = 30 , \text{m}^2 \]
Thus, the area of the triangular piece of land is \( 30 , \text{m}^2 \).