Answer:
[tex]21\%[/tex]
Step-by-step explanation:
Original dimensions of the rectangle
[tex]l=7\ \text{units}[/tex]
[tex]w=3\ \text{units}[/tex]
Area of the rectangle
[tex]A=7\times 3=21\ \text{units}^2[/tex]
Scale factor = 1.1
New dimensions
[tex]l'=7\times 1.1=7.7\ \text{units}[/tex]
[tex]w'=3\times 1.1=3.3\ \text{units}[/tex]
The new area of the rectangle
[tex]A'=7.7\times 3.3=25.41\ \text{units}^2[/tex]
Percentage change is given by
[tex]\dfrac{A'-A}{A}\times 100\\ =\dfrac{25.41-21}{21}\times 100=21\%[/tex]
The percentage by which the area of the rectangle increases is [tex]21\%[/tex].
