90,541 views
37 votes
37 votes
A rectangle is 20 meters long and 20 meters wide. If the length is increased by 10% and the width is decreased by 10%, what is the new area?

User MiBol
by
2.1k points

1 Answer

9 votes
9 votes

Consider that the initial length and width of the rectangle are given as,


\begin{gathered} l=20 \\ b=20 \end{gathered}

After the length is increased by 10%, the new length (L) of the rectangle is calculated as,


\begin{gathered} L=(1+(10)/(100))\cdot l \\ L=((110)/(100))\cdot20 \\ L=22 \end{gathered}

After the width is decreased by 10%, the new width (B) of the rectangle is calculated as,


\begin{gathered} B=(1-(10)/(100))\cdot b \\ B=((90)/(100))\cdot20 \\ B=18 \end{gathered}

Then the area (A) of the new rectangle is calculated as,


\begin{gathered} A=L* B \\ A=22*18 \\ A=396 \end{gathered}

Thus, the new area of the rectangle is 396 square meters.

User Ed Pike
by
3.3k points