안녕하세요.

아래함수를 사용해 보세요!

void __fastcall DrawArrow(TCanvas* Canvas, TPoint Start, TPoint Stop)
{
    double  Length = 10;
    double  r2;
    double  r3 = 15;

    if (Stop.x > Start.x)
        r2 = (180.0 * atan((double)(Stop.y - Start.y)
        / (double)(Start.x - Stop.x))) / 3.141519;
    else if (Stop.x < Start.x)
        r2 = ((180.0 * atan((double)(Stop.y - Start.y)
        / (double)(Start.x - Stop.x))) / 3.141519) + 180;
    else
    {
        if (Stop.y < Start.y)
            r2 = 90;
        else
            r2 = -90;
    }

    TPoint a, b;
    a = Point(Stop.x - (int)(Length * cos((3.141519 * (r2 + r3)) / 180)),
              Stop.y + (int)(Length * sin((3.141519 * (r2 + r3)) / 180)));

    b = Point(Stop.x - (int)(Length * cos((3.141519 * (r2 - r3)) / 180)),
              Stop.y + (int)(Length * sin((3.141519 * (r2 - r3)) / 180)));

    TPoint Points[3];
    Points[0] = Stop;
    Points[1] = a;
    Points[2] = b;

    Canvas->Brush->Color = clBlack;
    Canvas->Polygon(Points, 2);

    Canvas->MoveTo(Start.x, Start.y);
    Canvas->LineTo(Stop.x, Stop.y);


}