Let l = the lentth of the rectangle and w = the width of the rectangle; where w>0 and l>0;
We have 84 = l x w and l = 2 + w;
84 = (2+w) x w;
We solve the equation: w^2 + 2w - 84 = 0;
We obtain the solution w = 8.21;
The perimeter of the triangle is is 3 x 8.21 = 24.63;
