11. Possible answer: 12. A ≈ 4 ft2 Practice B 1. A = 1080 ft2 2. A = 6 in2 3. A 2= 3888 mm2 4. A ≈ 411.3 mi 5. A = 90 m2 6. A ≈ 27.5 yd2 7. A 2≈ 448.1 cm 8. A ≈ 1342.5 m2, or 9. $241.54 10. A ≈ 10 cm2 11. A ≈ 7.5 cm2 Practice C 1. 0.43 2. 0.55 3. 0.48 4. 0.83 5. Possible answer: xy 6. A ≈ 1.84 units2 7. A ≈ 1.14 units2 8. Possible answer: As the number of sides