Looking for correlation between length and angle











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The problem I'm facing might be rather easy to solve, but I can't think of a way how to do it atm. I want to clip straight 90-degree and some other degree lines. If I clip them at a fixed height (like h in the graphic) the 90-degree lines are too long.
So all I need to know is how to calculate the difference (x) which occurs if the line is not rotated by angle alpha.



Variables I know: alpha and h



sketch










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    up vote
    1
    down vote

    favorite












    The problem I'm facing might be rather easy to solve, but I can't think of a way how to do it atm. I want to clip straight 90-degree and some other degree lines. If I clip them at a fixed height (like h in the graphic) the 90-degree lines are too long.
    So all I need to know is how to calculate the difference (x) which occurs if the line is not rotated by angle alpha.



    Variables I know: alpha and h



    sketch










    share|cite|improve this question
























      up vote
      1
      down vote

      favorite









      up vote
      1
      down vote

      favorite











      The problem I'm facing might be rather easy to solve, but I can't think of a way how to do it atm. I want to clip straight 90-degree and some other degree lines. If I clip them at a fixed height (like h in the graphic) the 90-degree lines are too long.
      So all I need to know is how to calculate the difference (x) which occurs if the line is not rotated by angle alpha.



      Variables I know: alpha and h



      sketch










      share|cite|improve this question













      The problem I'm facing might be rather easy to solve, but I can't think of a way how to do it atm. I want to clip straight 90-degree and some other degree lines. If I clip them at a fixed height (like h in the graphic) the 90-degree lines are too long.
      So all I need to know is how to calculate the difference (x) which occurs if the line is not rotated by angle alpha.



      Variables I know: alpha and h



      sketch







      geometry angle






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      share|cite|improve this question










      asked Nov 22 at 16:25









      Sector

      254




      254






















          2 Answers
          2






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          The portion of the blue line segment between the vertex and the intersection with the dashed line must have length $x+h$, and that allows you to find $x$ like so:
          $$begin{align}
          cos(alpha)&=frac{h}{x+h} \[0.2ex]
          x+h&=hsec(alpha) \[0.7ex]
          x&=h(sec(alpha)-1)
          end{align}$$






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            Use Cosine(x) = adjacent / hypotenuse






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              2 Answers
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              active

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              2 Answers
              2






              active

              oldest

              votes









              active

              oldest

              votes






              active

              oldest

              votes








              up vote
              1
              down vote



              accepted










              The portion of the blue line segment between the vertex and the intersection with the dashed line must have length $x+h$, and that allows you to find $x$ like so:
              $$begin{align}
              cos(alpha)&=frac{h}{x+h} \[0.2ex]
              x+h&=hsec(alpha) \[0.7ex]
              x&=h(sec(alpha)-1)
              end{align}$$






              share|cite|improve this answer

























                up vote
                1
                down vote



                accepted










                The portion of the blue line segment between the vertex and the intersection with the dashed line must have length $x+h$, and that allows you to find $x$ like so:
                $$begin{align}
                cos(alpha)&=frac{h}{x+h} \[0.2ex]
                x+h&=hsec(alpha) \[0.7ex]
                x&=h(sec(alpha)-1)
                end{align}$$






                share|cite|improve this answer























                  up vote
                  1
                  down vote



                  accepted







                  up vote
                  1
                  down vote



                  accepted






                  The portion of the blue line segment between the vertex and the intersection with the dashed line must have length $x+h$, and that allows you to find $x$ like so:
                  $$begin{align}
                  cos(alpha)&=frac{h}{x+h} \[0.2ex]
                  x+h&=hsec(alpha) \[0.7ex]
                  x&=h(sec(alpha)-1)
                  end{align}$$






                  share|cite|improve this answer












                  The portion of the blue line segment between the vertex and the intersection with the dashed line must have length $x+h$, and that allows you to find $x$ like so:
                  $$begin{align}
                  cos(alpha)&=frac{h}{x+h} \[0.2ex]
                  x+h&=hsec(alpha) \[0.7ex]
                  x&=h(sec(alpha)-1)
                  end{align}$$







                  share|cite|improve this answer












                  share|cite|improve this answer



                  share|cite|improve this answer










                  answered Nov 22 at 16:48









                  Robert Howard

                  1,9181822




                  1,9181822






















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                      Use Cosine(x) = adjacent / hypotenuse






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                        up vote
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                        down vote













                        Use Cosine(x) = adjacent / hypotenuse






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                          up vote
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                          up vote
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                          Use Cosine(x) = adjacent / hypotenuse






                          share|cite|improve this answer












                          Use Cosine(x) = adjacent / hypotenuse







                          share|cite|improve this answer












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                          answered Nov 22 at 16:28









                          John McGee

                          1361




                          1361






























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