Answer:
The length is increased by 5 feet and width is increased by 7 feet.
Explanation:
Given:
Length of section is twice the width.
During sale the section is expanded to an area =

To find increase in length and width.
Solution:
Let the length of the section be =

width of the section =

Expression for area :

Factoring:



So, area of the section after increase can be given as

We know that length is twice the width, which means:

Substituting the value of
in the factored expression of area.

Since area of triangle is product of length and width, so we have:
New length of section =

New width of the section =

Thus, length is increased by 5 feet and width is increased by 7 feet.