The Area of an Equilateral Triangle with side length s is given as:
![A=\frac{\sqrt[]{3}}{4}s^2](https://img.qammunity.org/2023/formulas/mathematics/college/q8352b87yky33mhtkcbwiwnq351sngpg92.png)
Substitute s=16 into the equation:
![\begin{gathered} A=\frac{\sqrt[]{3}}{4}(16)^2=\frac{\sqrt[]{3}*16*16}{4} \\ A=\frac{\sqrt[]{3}*\cancel{16}^4*16}{\cancel{4}^1}=\sqrt[]{3}*4*16\approx110.85\text{ square feet} \end{gathered}](https://img.qammunity.org/2023/formulas/mathematics/college/y4b62xz3y35k0h87vxexfrkmer69evxfoq.png)
The area of the window is about 110.85 ft².
Since it is given that glass costs $20.25 per square foot, it follows that the replacement will cost:

The cost of the replacement window is about $2,244.71