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anonymous

  • 5 years ago

Please help.. I need to find the area of the shaded regions. could you please show me how you get the answer so i know how to

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  1. anonymous
    • 5 years ago
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  2. amistre64
    • 5 years ago
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    the area of a sector as in #26 is given by the formula (radian angle) times r^2 divided by 2. You have 2 different "radiuses" in #26 so we just take the larger area with radius (R) and subtract the inner/smaller area with radius (r) from it and your left with the shaded area. What are the Radiusesses involved in #26?

  3. anonymous
    • 5 years ago
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    8 and 2

  4. amistre64
    • 5 years ago
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    Diameter is 8; radius is half of that = 4; inner radius is 4. Add 2 to that to get 6 for the outer radius. Does this make sense so far?

  5. anonymous
    • 5 years ago
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    ya

  6. amistre64
    • 5 years ago
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    good; the shaded area is actually the area of half of a circle. if that makes sense; radian measurement is pi. Outer area - inner area = shaded area 6^2pi/2 - 4^2pi/2 = ShA 36pi/2 - 16pi/2 = ShA 18pi - 8pi = ShA 10pi is the area of the shaded region of #26.

  7. anonymous
    • 5 years ago
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    so 10*pi?

  8. amistre64
    • 5 years ago
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    yes; 10*pi should be the area of the shaded portion in #26

  9. anonymous
    • 5 years ago
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    so 31.4

  10. amistre64
    • 5 years ago
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    if we are going to use 3.14 to equal pi; then you are correct.

  11. anonymous
    • 5 years ago
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    okay

  12. amistre64
    • 5 years ago
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    #27 seems to be missing a measurement. the inner shading is 1 cm radius; and the total outer is 7 cm radius; but what would the radius be for the middle section?

  13. anonymous
    • 5 years ago
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    it doesnt say

  14. amistre64
    • 5 years ago
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    I cant see a way to figure it out with those measurements alone. maybe im missing something... lets try #28

  15. anonymous
    • 5 years ago
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    ok

  16. amistre64
    • 5 years ago
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    that is the area of the isoTriangle - the area of the inner circle, just gotta recall how to find area of the isoTriangle..

  17. amistre64
    • 5 years ago
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    the triangle should have an area of: 21 + 7sqrt(3)/2 and we subtract 36pi from it to get the shaded area.

  18. amistre64
    • 5 years ago
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    are there any "multiple choice" answers to choose from?

  19. anonymous
    • 5 years ago
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    no

  20. anonymous
    • 5 years ago
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    k

  21. amistre64
    • 5 years ago
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    27.06217782 - 36pi does not seem correct....gonna have to try again :)

  22. anonymous
    • 5 years ago
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    its 27.73883783

  23. amistre64
    • 5 years ago
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    108sqrt(3) - 36pi...

  24. anonymous
    • 5 years ago
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    ok

  25. amistre64
    • 5 years ago
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    I get 73.96 as long as I did it right :)

  26. anonymous
    • 5 years ago
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    ok

  27. amistre64
    • 5 years ago
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    and I get: 36pi - 18pi - 18 18pi -18 18(pi -1) 18(2.14) = 38.52 thats the best I can do fer ya :)

  28. anonymous
    • 5 years ago
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    for what one?

  29. amistre64
    • 5 years ago
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    #29...but I gotta recalculate.. it should end up being: 18(pi - 2) 18(1.14) = 20.52 I lost track of one of my sectors :)

  30. amistre64
    • 5 years ago
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    6*6 = 36; thats a square area; pi(36)/4 = 9pi = 1 sector pi(36)/4 = 9pi = another sector both sectors together are 18pi. 36pi - 18pi - 36 18pi - 36 18(pi - 2) 18(1.14) = 20.52

  31. amistre64
    • 5 years ago
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    thats all I can help you with; hope it helps :)

  32. anonymous
    • 5 years ago
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    okay thank you

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