Another math challenge
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2007-02-23 02:44 AM
2007-02-23
02:44 AM
if someone could help I would appreciate
ta
X1,Y1,X2,Y2,X3,Y3 - known
Xa,Ya,Xb,Yb - known
Xc,Yc - ???
::rk
8 REPLIES 8
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2007-02-23 10:44 AM
2007-02-23
10:44 AM
You should be able to calculate it by pythagoras and TAN. I have added some length (L,r), which are known out of your settings
bim author since 1994 | bim manager since 2018 | author of selfGDL.de | openGDL | skewed archicad user hall of fame | author of bim-all-doors.gsm
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2007-02-23 11:03 AM
2007-02-23
11:03 AM
I appologise, I have forgotten to mention that alpha is not known, it's there just to demonstrate the centerline of the angle.
::rk
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2007-02-23 11:36 AM
2007-02-23
11:36 AM
Are you shure that the both distances L are identical? Elsewhere the center line and alpha is not the only problem. 😉
bim author since 1994 | bim manager since 2018 | author of selfGDL.de | openGDL | skewed archicad user hall of fame | author of bim-all-doors.gsm
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2007-02-23 11:41 AM
2007-02-23
11:41 AM
yep, the L distances are identical
::rk

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2007-02-24 02:34 PM
2007-02-24
02:34 PM
I think if you know the coordinates of all three corners of the triangle, you should be able to find out any of the angles of the triangle. Alpha will be half of the angle at point 2.
Loving Archicad since 1995 - Find Archicad Tips at x.com/laszlonagy
AMD Ryzen9 5900X CPU, 64 GB RAM 3600 MHz, Nvidia GTX 1060 6GB, 500 GB NVMe SSD
2x28" (2560x1440), Windows 10 PRO ENG, Ac20-Ac28
AMD Ryzen9 5900X CPU, 64 GB RAM 3600 MHz, Nvidia GTX 1060 6GB, 500 GB NVMe SSD
2x28" (2560x1440), Windows 10 PRO ENG, Ac20-Ac28
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2007-02-25 10:34 AM
2007-02-25
10:34 AM
I think if you know the coordinates of all three corners of the triangle, you should be able to find out any of the angles of the triangle. Alpha will be half of the angle at point 2.thanks laszlo for your suggeston, it did not solve the problem, however it gave me the starting idea and finally solution after couple hours of sketching and calculating.
::rk
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2007-02-26 11:33 AM
2007-02-26
11:33 AM
You can also avoid Alpha:
!-------------------------------------------------------
! (X0, Y0) is the center of the arc
! D = distance betwen center and point (X2,Y2)
!--------------------------------------------------------
R^2 = (Xa-X0)^2 + (Ya-Y0)^2
R^2 = (Xb-X0)^2 + (Yb-Y0)^2
L^2 = (Xa-X2)^2 + (Ya-Y2)^2
L^2 = (Xb-X2)^2 + (Yb-Y2)^2
D^2 = R^2 + L^2
5 unkowns & 5 Equations, solvable.......
!-------------------------------------------------------
! (X0, Y0) is the center of the arc
! D = distance betwen center and point (X2,Y2)
!--------------------------------------------------------
R^2 = (Xa-X0)^2 + (Ya-Y0)^2
R^2 = (Xb-X0)^2 + (Yb-Y0)^2
L^2 = (Xa-X2)^2 + (Ya-Y2)^2
L^2 = (Xb-X2)^2 + (Yb-Y2)^2
D^2 = R^2 + L^2
5 unkowns & 5 Equations, solvable.......

Howard Phua
Win 10, Archicad 19 INT
Win 10, Archicad 19 INT
Anonymous
Not applicable
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2010-01-20 07:48 PM
2010-01-20
07:48 PM
I know the post I'm adding to is old, but it's related.
I was working on a much simplified detail symbol which shows the clip polygon with filleted corners. I managed to figure out how to draw the clip polygon, . Simple enough, you just put the clip coordinates into memory and draw a polygon but I could not figure out how to add the nodes to create filleted coners.
I attached the library part, but following is the"for next" loop that extracts the clip polygon.
add2 AC_RefCoord[1][1], AC_RefCoord[1][2]
for i=1 to AC_ClippNodes
if i<>AC_ClippNodes then
put AC_ClippCoord[1],AC_ClippCoord[2],1
next i
poly2_ AC_ClippNodes, 1,
get(nsp)
I was working on a much simplified detail symbol which shows the clip polygon with filleted corners. I managed to figure out how to draw the clip polygon, . Simple enough, you just put the clip coordinates into memory and draw a polygon but I could not figure out how to add the nodes to create filleted coners.
I attached the library part, but following is the"for next" loop that extracts the clip polygon.
add2 AC_RefCoord[1][1], AC_RefCoord[1][2]
for i=1 to AC_ClippNodes
if i<>AC_ClippNodes then
put AC_ClippCoord
next i
poly2_ AC_ClippNodes, 1,
get(nsp)