ne Practice 13-3 erimeter the perimeter of each figure. 3 cm 7.5 mm 7 km 3 cm 1 m 2 m 5 mm 5 cm 7 km 3 m 7 km 7.5 mm 7 km 2 m + 5. Number Sense What is the perimeter of a square if one of the sides is 3 mi? 30 Ft 30 ft he dimensions of a football field re shown at the right. 300 6