A rectangle with dimensions of 3 units by 7 units is enlarged by a scale factor of 1.1. By what percent does it’s area increase?

Question

asked Jan 19, 2022 103k views

1 Answer

Misorude · Answer 1 · 2022-01-24T17:08:34+0000

Answer:

$21\%$

Explanation:

Original dimensions of the rectangle

$l=7\ \text{units}$

$w=3\ \text{units}$

Area of the rectangle

$A=7* 3=21\ \text{units}^2$

Scale factor = 1.1

New dimensions

$l'=7* 1.1=7.7\ \text{units}$

$w'=3* 1.1=3.3\ \text{units}$

The new area of the rectangle

$A'=7.7* 3.3=25.41\ \text{units}^2$

Percentage change is given by

$(A'-A)/(A)* 100\\ =(25.41-21)/(21)* 100=21\%$

The percentage by which the area of the rectangle increases is
$21\%$ .