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Thread: Perimeter of polygon and area of triangle

  1. #1
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    Default Perimeter of polygon and area of triangle

    Hello:
    Need help to figure out why my code fail to compile in the following functions:

    perimeter = perimeter + yc[i].distanceTo(yc[i+1]); //get polygon perimeter

    area = x1 * (y2 - y3) + x2 * (y3 - y1) + x3 * (y1 - y2) / 2; //get area triangle

    here is my code:
    Last edited by term204; April 15th, 2018 at 08:19 PM.

  2. #2
    Super Moderator Norm's Avatar
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    Default Re: Perimeter of polygon and area of triangle

    why my code fail to compile
    Please copy the full text of the error message and paste it here. It has important info about the error(s).
    If you don't understand my answer, don't ignore it, ask a question.

  3. #3
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    Default Re: Perimeter of polygon and area of triangle

    Here is the error:

    Herencia.java:109: error: array required, but double found
    perimeter = perimeter + yc[i].distanceTo(yc[i+1]);
    ^
    Herencia.java:109: error: array required, but double found
    perimeter = perimeter + yc[i].distanceTo(yc[i+1]);
    ^
    Herencia.java:156: error: cannot find symbol
    area = x1 * (y2 - y3) + x2 * (y3 - y1) + x3 * (y1 - y2) / 2;
    ^
    symbol: variable x1
    location: class Triangulo
    Herencia.java:156: error: cannot find symbol
    area = x1 * (y2 - y3) + x2 * (y3 - y1) + x3 * (y1 - y2) / 2;
    ^
    symbol: variable y2
    location: class Triangulo
    Herencia.java:156: error: cannot find symbol
    area = x1 * (y2 - y3) + x2 * (y3 - y1) + x3 * (y1 - y2) / 2;
    ^
    symbol: variable y3
    location: class Triangulo
    Herencia.java:156: error: cannot find symbol
    area = x1 * (y2 - y3) + x2 * (y3 - y1) + x3 * (y1 - y2) / 2;
    ^
    symbol: variable x2
    location: class Triangulo
    Herencia.java:156: error: cannot find symbol
    area = x1 * (y2 - y3) + x2 * (y3 - y1) + x3 * (y1 - y2) / 2;
    ^
    symbol: variable y3
    location: class Triangulo
    Herencia.java:156: error: cannot find symbol
    area = x1 * (y2 - y3) + x2 * (y3 - y1) + x3 * (y1 - y2) / 2;
    ^
    symbol: variable y1
    location: class Triangulo
    Herencia.java:156: error: cannot find symbol
    area = x1 * (y2 - y3) + x2 * (y3 - y1) + x3 * (y1 - y2) / 2;
    ^
    symbol: variable x3
    location: class Triangulo
    Herencia.java:156: error: cannot find symbol
    area = x1 * (y2 - y3) + x2 * (y3 - y1) + x3 * (y1 - y2) / 2;
    ^
    symbol: variable y1
    location: class Triangulo
    Herencia.java:156: error: cannot find symbol
    area = x1 * (y2 - y3) + x2 * (y3 - y1) + x3 * (y1 - y2) / 2;
    ^
    symbol: variable y2
    location: class Triangulo
    11 errors

  4. #4
    Super Moderator Norm's Avatar
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    Default Re: Perimeter of polygon and area of triangle

    Herencia.java:109: error: array required, but double found
    perimeter = perimeter + yc[i].distanceTo(yc[i+1]);
    ^
    Primitive variables do not have methods. yc[i] is a double. double is a primitive
    What are you trying to do in that statement.

    Herencia.java:156: error: cannot find symbol
    The compiler can not find a definition for the variable named in those error messages. Make sure the variables are defined in scope where they are being used. In scope means within the same pair of {}s.
    If you don't understand my answer, don't ignore it, ask a question.

  5. The Following 2 Users Say Thank You to Norm For This Useful Post:

    term204 (April 15th, 2018)

  6. #5
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    Default Re: Perimeter of polygon and area of triangle

    What are you trying to do in that statement.
    I do not know the formula to get the perimeter of the polygon.. i found similar code on internet and i try to insert here..

    The compiler can not find a definition for the variable named in those error messages. Make sure the variables are defined in scope where they are being used. In scope means within the same pair of {}s.
    Thanks

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    Default Re: Perimeter of polygon and area of triangle

    We need to see more code in order to solve
    Whatever you are, be a good one

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