Final answer:
The area covered by the stained glass window is approximately 18521.98 square inches.
Step-by-step explanation:
To find the area covered by the stained glass window, we need to find the area of the regular octagon. The formula to find the area of a regular octagon is:
Area = (2 + 2√2) × s²
where s is the length of a side.
Given that the side length of the octagon is 18 inches, we can substitute this value into the formula:
Area = (2 + 2√2) × 18²
Simplifying the expression:
Area = (2 + 2√2) × 324
Calculating the area:
Area ≈ 18521.98 square inches