**Solution**

Here base of triangle $=7.5 \mathrm{~cm}$, height of triangle $=4 \mathrm{~cm}$

Area of triangle $=\frac{1}{2} \times$ base $\times$ height

$$

\begin{array}{l}

=\frac{1}{2} \times(7.5 \mathrm{~cm}) \times 4 \mathrm{~cm} \\

=15 \mathrm{~cm}^{2}

\end{array}

$$