1) The perimeter of a semicircle is the sum of the length of the curved part (half the circumference of a full circle) and the diameter. The formula for the circumference of a full circle is C = πd, where d is the diameter. For a semicircle, the curved part is (πd)/2. Adding the diameter gives the total perimeter: Perimeter = (πd)/2 + d. For a diameter of 8 ft, the calculation is (π × 8)/2 + 8 = 4π + 8. Using π ≈ 3.14, this is 4 × 3.14 + 8 = 12.56 + 8 = 20.56 ft. Rounding to the nearest foot gives 21 ft.
2) The perimeter of a semicircle is the sum of the length of the curved part (half the circumference of a full circle) and the diameter. The formula for the circumference of a full circle is C = 2πr, where r is the radius. For a semicircle, the curved part is πr. Adding the diameter (2r) gives the total perimeter: Perimeter = πr + 2r. For a radius of 10 inches, the calculation is π × 10 + 2 × 10 = 10π + 20. Using π ≈ 3.14, this is 10 × 3.14 + 20 = 31.4 + 20 = 51.4 inches. Rounding to 1 decimal place gives 51.4 inches.
3) The perimeter of a semicircle is the sum of the length of the curved part (half the circumference of a full circle) and the diameter. The formula for the circumference of a full circle is C = πd, where d is the diameter. For a semicircle, the curved part is (πd)/2. Adding the diameter gives the total perimeter: Perimeter = (πd)/2 + d. For a diameter of 32 yards, the calculation is (π × 32)/2 + 32 = 16π + 32. Using π ≈ 3.14, this is 16 × 3.14 + 32 = 50.24 + 32 = 82.24 yards. Rounding to the nearest yard gives 82 yards.
Parent Tip: Review the logic above to help your child master the concept of semicircle worksheet.
