Question

A landscaper has 125 times to build a square patio the patio must have an area of at least 80 ft.² hey. What are the possible arrangements for the patio b. How many tiles are not using each arrangement

Answer 1

QA. 
Assuming the dimensions have to be in exact feet then you could have 
9ft *9ft = 81square feet 
10 ft * 10 ft = 100 square feet 
11 ft * 11 ft = 121 square feet. 

QB. 
If each tile is 1 ft * 1 ft ie 1 square foot 
Then 
9' * 9' would mean 125 - 81 = 44 tiles would not be used 
10' * 10' = 125 - 100 = 25 tiles not used 
11' * 11' = 125 - 121 = 4 tiles not used