if the tension in an elastic rodis doubled while the overall length of the rod is held constant, the energy stored in the rod is doubled, is it true or false​

The length of each side of a square is 1 centimeter more than the width of the rectangle. the length of the rectangle is 1 centimeter less than twice it’s width. the perimeters of the two figures are equal. determine the measures of the side lengths of the rectangle. show all work i have a test tomorrow