1. The area is 81 square feet. The formula for the area of a square is side × side. Since each side is 9 feet, the calculation is 9 × 9 = 81 sq ft.
2. The perimeter is 22 centimeters. The formula for the perimeter of a rectangle is 2 × (length + width). With a length of 7 cm and a width of 4 cm, the calculation is 2 × (7 + 4) = 2 × 11 = 22 cm.
3. The width is 10 cm. Assuming the book is rectangular and its length is 10 cm (a common size for such problems), the perimeter formula is 2 × (length + width). Given the perimeter is 40 cm, we have 40 = 2 × (10 + width). Solving for width: 40 ÷ 2 = 20, then 20 - 10 = 10 cm. (Note: The problem does not specify the length, so this assumes a typical value; if length were different, width would adjust accordingly).
4. There are multiple possible answers. For a rectangle with a perimeter of 70 cm, the sum of the length and width must be 35 cm (since perimeter = 2 × (length + width)). Any pair of positive numbers that add to 35 cm can be the length and width (e.g., 10 cm and 25 cm, or 15 cm and 20 cm).
5. The perimeter is 52 centimeters. Using the perimeter formula for a rectangle: 2 × (length + width) = 2 × (24 + 2) = 2 × 26 = 52 cm.
6. The perimeter is 220 meters. Using the perimeter formula for a rectangle: 2 × (length + width) = 2 × (75 + 35) = 2 × 110 = 220 m.
Parent Tip: Review the logic above to help your child master the concept of perimeter worksheet 4th grade.
