Answer:
To find the area of the extension, I'm going to find the total area (patio and extension) and subtract the patio.
Total area: length = 1.5 + 6.25 + 1.5 = 9.25 height = 1.5 + 6.25 = 7.75
Total Area = 9.25 x 7.75 = 71.6875
Area of the patio = 6.25 x 6.25 = 39.0625
Area of the extension = Total Area - Area of the patio = 71.6875 - 39.0625 = 32.625
Area covered by one box of tiles: 25 x 0.25 x 0.25 = 1.5625
Number of boxes needed: 32.625 / 1.5625 = 20.88 = 21 boxes
Explanation: