A rectangle is split in half by a diagonal line creating two triangles The perimeter of a rectangle is 28 cm. The perimeter of each of the triangles is 24 cm. The diagonal of the reactangle is 2cm longer then the longer side of the rectangle. Find the length of the Diagonal. Ive tried trial and error of numbers, and i think i get it correct. Long sides of Rectangle= 8cm. Short Sides of rectangle= 4cm This gives a perimeter of 28. If the Long side of rectangle is 8. then the diagonal would be 10cm. it Follows the Pathagerom Thereom.. but how would i go about solving this using three equations, with three unkown's..