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Math Help - Urgent 5 perimeter and area questions

  1. #1
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    Urgent 5 perimeter and area questions

    Could you take a look at the attachment and let me know what to do?

    Also would this be correct?
    [FONT='Arial','sans-serif']NDBA is a rectangle with parallelogram GDFA enclosed. If[/FONT][FONT='Arial','sans-serif'] AN = NG, BF = DB, GD = 11, and DF = 8√2. What is the area of GDFA?[/FONT]
    Area = height *base
    Base=GD=AF=11
    DBF is an isosceles right triangle so DB=FB. To get DF take x2+x2=([FONT='Arial','sans-serif']8√2)2=2x2=128 so x=8[/FONT]
    [FONT='Arial','sans-serif']Would this make the area 88?[/FONT]
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  2. #2
    Super Member malaygoel's Avatar
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    1st question

    You got AB right. It is 24.
    in DBC, BC is 24, hence the sum of other two sides is 50-24=26.
    Sincs DBC is isosceles the other two sides are 13 and 13.
    Hence the answer is 24+13=37

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  3. #3
    Super Member malaygoel's Avatar
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    2nd question

    The are two distinct sides in parallelogram.
    One you got right..it is 12.
    To find the other, we use perimeter of parallelogram
    P=2(a+b)
    60=2(12+b)
    b=18.

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  4. #4
    Member Ranger SVO's Avatar
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    Can I try #1? Triangle ABC is an equalateral so each side is 24. Triangle DBC is an isosceles with base BC which is 24. The perimeter of Triangle DBC is 50

    We have 2 unknown sides + the base which equals the perimeter

    So 2*a + 24 = 50 What we should get is a = 13

    So AB + BD = 37 because 24 + 13 = 37
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  5. #5
    Super Member malaygoel's Avatar
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    3rd question

    You need to know the following thing to solve the question

    If O is the mid-point of KN, it impies KO=ON.

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  6. #6
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    Hello, Sanee!

    C. In the trapezoid KLMN, OP joins the midpoints of two sides, and KL +MN \:=\:32

    If KO + PM \:=\:11, which is the perimeter of the trapezoid?

    . . a)\;43\qquad b)\;44\qquad c)\;54\qquad d)\;58
    Code:
                  K     L
                    *  
                 *        *
                *           *
               *              *
             O  *  *  *  *  *  P
             *                    *
            *                       *
           *                          *
            *  *  *  *  *  *  *  *  *  
          N                             M
    They gave us: . KL + MN \:=\:32
    . . We have the total length of the two parallel sides.


    They gave us: . KO +PM\:=\:11

    Since O and P are midpoints: . \begin{array}{ccc}KO \,= \,\frac{1}{2}KN & \Rightarrow & KN \,= \,2\!\cdot\!KO \\PM \,= \,\frac{1}{2}LM & \Rightarrow & LM \,= 2\!\cdot\! PM\end{array}

    Hence: . KN + LM \:=\:2\!\cdot\!KO + 2\!\cdot\!PM \:=\:2(KO + PM) \:=\:2(11) \:=\:22
    . . And we have the total length of the two nonparallel sides.


    Therefore, the perimeter is: . 32 + 22 \:=\:54\;\;(c)

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  7. #7
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    [FONT='Times New Roman','serif']Area of the of square P is 36 square inches and the perimeter of the rectangle R is 144 inches. If a width of the rectangle is two times a length of the square, which is the length of a length of the rectangle?
    [FONT='Times New Roman','serif']70,60,45,30[/FONT]
    [/FONT]
    [FONT='Times New Roman','serif']If the area is 36 then each side is 9 square inches. the perimeter is 144 with a width of 2*9.[/FONT]
    [FONT='Times New Roman','serif']Then 144=2(18+b) gets to be b=54 Where am I wrong at?[/FONT]
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  8. #8
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    Hello, Sanee!

    Area of the of square P is 36 in
    and the perimeter of the rectangle R is 144 inches.
    If a width of the rectangle is two times a length of the square,
    which is the length of a length of the rectangle?
    . . a)\;70\qquad b)\;60\qquad c)\;45\qquad d)\;30

    If the area is 36, then each side is 9 inches. . ← Here!

    The area is 36 in, so the side is six inches.

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  9. #9
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    Angry

    So the perimeter of the rectangle is 144=2(6+b) 144=12+2b 132=2b b=66 which is still not an answer I can choose from, what now?
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  10. #10
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    Smile

    duhh
    144=2(12+b) 144=24+2b 120=2b b=60
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