A field is in the form of a right triangle with hypotenuse 50 m and one side 30 m.

Let the other side of the triangular field be $x \mathrm{~m}$.

$\therefore x^{2}=\left\{(50)^{2}-(30)^{2}\right\}$

$\Rightarrow x^{2}=(2500-900)$ $\Rightarrow x^{2}=1600$

$\Rightarrow x=\sqrt{1600}$

$\Rightarrow x=40$

$\therefore A$ rea of the field $=\left(\frac{1}{2} \times 30 \times 40\right) \mathrm{m}^{2}$

$=600 \mathrm{~m}^{2}$