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repost:: geometry question
Posted:
Jul 11, 1996 1:34 AM
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In three-space, if the angles between three unit vectors from the origin
are known and the first two unit vectors are determined, how can I
determine the third vector? This is a repost of my soccer ball (truncated
icosahedron) question from a few days ago. I calculated the angles
incorrectly in the previous post. Perhaps that is why it stumped
everyone.
The first two vectors are in the XY plane at 126ÃÂú and 234ÃÂú from the +X
axis. A third is along the +X axis at some angle above the XY plane. It
is 120ÃÂú from either of the other vectors. What is the angle above the XY
plane of the third vector?
^ | define third unit vector?
| +X |
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(hexagon portion) 120ÃÂú / \ 120ÃÂú (hexagon portion)
/ / 108ÃÂú (pentagon
portion)
Assume pentagon lies in XY plane.
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