Re^4: (OT) moving points from one plane to another

It is a part geometry problem where the basic profile is defined in one plane but is used in another plane.
Do you know if I am correct in thinking that the angle between the two planes is the dot product of the normals to the two planes?

Comment on Re^4: (OT) moving points from one plane to another

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Re^5: (OT) moving points from one plane to another by BrowserUk (Patriarch) on Jul 09, 2009 at 13:09 UTC
the angle between the two planes is the dot product of the normals to the two planes? Correct. Examine what is said, not who speaks -- Silence betokens consent -- Love the truth but pardon error. "Science is about questioning the status quo. Questioning authority". In the absence of evidence, opinion is indistinguishable from prejudice. RIP PCW	[reply]
Re^5: (OT) moving points from one plane to another by assemble (Friar) on Jul 09, 2009 at 15:34 UTC
No! The angle between the normals is the angle between the two planes, but you don't get angles out of a dot product! If θ is the angle between the planes: θ = cos^-1((n₁.n₂)/(\|n₁\|\|n₂\|)) This formula is based on one of the definitions of the dot product, which states: n₁.n₂=\|n₁\|\|n₂\|cos(θ)	[reply]