The length and width of a rectangle are increased by 4cm, and the area is increased by 80cm

The length and width of a rectangle are increased by 4cm, and the area is increased by 80cm

The length and width of a rectangle are increased by 4cm
It can be seen from the drawing that the area increases: 4 length + 4 width + 4 × 4 = 80 cm
It is known that length + width = 16 cm
The perimeter of the original rectangle is 16 × 2 = 32 square centimeters