Two rectangles have the same perimeter 640cm, the length of one rectangle is 12dm

Two rectangles have the same perimeter 640cm, the length of one rectangle is 12dm and the other 10dm, which rectangle has more area.

1. 640 centimeters / 10 = 64 decimeters.

2. Knowing the perimeters of the rectangles and one of the sides, we find the second side (we denote x – the second side):

1 rectangle: 64 = 12 + 12 + 2x; x = 20 decimeters.

2 rectangle: 64 = 10 + 10 + 2x; x = 22 decimetres.

3. Knowing the sides of the rectangles, we find the area of each of them:

1 rectangle: 20 * 12 = 240 decimeters.

2 rectangle: 22 * 10 = 220 decimeters.

4. 240 is greater than 220, which means that the area of 1 rectangle is greater than the area of the second.