Answer:
30%
Step-by-step explanation:
Initial area is 40 square feet
Final area is 28 square feet
Difference between the initial and final areas will be 40-28=12 square feet
Taking the initial area as the base area and expressing the area change in percentage then the percentage decrease will be equivalent to
[tex]\frac {12\times 100}{40}=30[/tex]
Therefore, the decrease in area expressed as a percentage is equal to 30%
