Step-by-step explanation:
[tex]Area \: of \: window \\ = \frac{1}{2} \times (9 + 4.5) \times 7 \\ = \frac{1}{2} \times 13.5 \times 7 \\ = \frac{1}{2} \times 94.5 \\ = 47.25 \: {in}^{2} \\ \orange {\boxed{\therefore \: Area \: of \: window = 47.25 \: {in}^{2}}}[/tex]