The sum of the perimeters of an equilateral triangle and a rectangle is 90 cm. Thearea, T, of the triangle and the area, R, of the rectangle, both in sq cm, satisfy therelationship R = T2 . If the sides of the rectangle are in the ratio 1: 3, then the length, in cm,of the longer side of the rectangle, is
Correct answer is option 'B'. Can you explain this answer?