Question 1052659
Squares have equal sides.
Do you mean you have a rectangle with an area of {{{24*35}}} that you need to convert to a triangle of minimum perimeter?
I'll assume that's what you mean, you can repost if my assumption was incorrect.
A triangle of minimum perimeter would be an equilateral triangle. 
So the area of an equilateral triangle is,
{{{A[ET]=(sqrt(3)/4)(s^2)}}}

{{{(sqrt(3)/4)s^2=24*35}}}
{{{s^2=1120sqrt(3)}}}
{{{s=4sqrt(70)sqrt(sqrt(3))}}}
or approximately 
{{{s=44}}}{{{ft}}}