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I don't understand this please help

I don't understand this please help-example-1
User Spbsmile
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2 Answers

5 votes
Circle area equation is 3.14 x r squared.
So for question 1,
The radius is 3 cm.
We can square the radius ( 3 squared = 9).
After that, 9 x 3.14 = 28.26.

And after that we match our answers on the right hand column. Since we don't have the answer as given, we try to look for similar numbers. If we look at H, it shows us 0.2826 km squared. When cm is turned into km, the decimal moves two digits to its left. So for question 1, H is correct.
User Aaron Balthaser
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5.7k points
5 votes
1. A = πr²
A = 3.14 × 3²
A= 28.26 cm²

2. A = πr²
A = 3.14 × 4²
A= 50.24 in²

3. A = πr²
A = 3.14 × 10²
A= 314 m²

4. A = πr²
A = 3.14 × 2²
A= 12.56 cm²

5. A = πr²
A = 3.14 × 9²
A= 254.34 ft²

6. A = πr²
A = 3.14 × 1.2²
A= 4.5216 km²

7. A = πr²
A = 3.14 × 50²
A= 7850 in²

8. A = πr²
A = 3.14 × 11²
A= 379.94 m²

9. A = πr²
A = 3.14 × 2.5²
A= 19.625 cm²

10. A = πr²
A = 3.14 × 7²
A= 153.86 in²

11. A = πr²
A = 3.14 × 5²
A= 78.5 cm²

12. A = πr²
A = 3.14 × 1.5²
A= 78.5 m²

13. A = πr²
A = 3.14 × 8²
A= 200.96 ft²

14. A = πr²
A = 3.14 × 20²
A= 62.8 m²

15. A = πr²
A = 3.14 × 6²
A= 113.04 in²

16. A = πr²
A = 3.14 × 3.5²
A= 38.465 cm²

17.A = πr²
A = 3.14 × 0.3²
A= 0.2826 km²

18. A = πr²
A = 3.14 × 1²
A= 3.14 m²
User CARCARLO
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5.7k points