Question

Find the surface area of each figure (spheres and hemispheres)

Answer 1

Answer:

7. 1520.53 cm²

8. 232.35 ft²

9. 706.86 m²

10. 4,156.32 mm²

11. 780.46 m²

12. 1,847.25 mi²

Step-by-step explanation:

Recall:

Surface area of sphere = 4πr²

Surface area of hemisphere = 2πr² + πr²

7. r = 11 cm

Plug in the value into the appropriate formula

Surface area of the sphere = 4*π*11² = 1520.53 cm² (nearest tenth)

8. r = ½(8.6) = 4.3 ft

Plug in the value into the appropriate formula

Surface area of the sphere = 4*π*4.3² = 232.35 ft² (nearest tenth)

9. r = ½(15) = 7.5 m

Surface area of the sphere = 4*π*7.5² = 706.86 m² (nearest tenth)

10. r = ½(42) = 21 mm

Plug in the value into the formula

Surface area of hemisphere = 2*π*21² + π*21² = 2,770.88 + 1,385.44

= 4,156.32 mm²

11. r = 9.1 m

Plug in the value into the formula

Surface area of hemisphere = 2*π*9.1² + π*9.1² = 520.31 + 260.15

= 780.46 m²

12. r = 14 mi

Plug in the value into the formula

Surface area of hemisphere = 2*π*14² + π*14² = 1,231.50 + 615.75

= 1,847.25 mi²