Mike built a sand castle that measured 484 centimetres by 386 centimetres, and dug a moat around it. Afterward, he decided to change the castle size, making it 725 centimetres by 314 centimetres. How much longer will the newer moat be than the older one?

the newer moat is 169 cm longer than the older one

Step-by-step explanation:

in order to find the difference in length of the two castles, we will first find the perimeters of the two castles then calculate the difference in the perimeters:

old castle:

dimension = 484cm by 386cm

perimeter = 484 + 386 = 870 cm

new castle:

dimension = 725cm by 314cm

perimeter = 725 + 314 = 1039 cm

difference = 1039 - 870 = 169 cm

The total length of the moats used is equals to the perimeter of the sand castles, therefore, the newer moat is 169 cm longer than the older one.