tangent and coincident constraints

wayne_pinnow

if a line has a tangent constraint to a circle, is it necessary for the endpoint of the line to also have a coincident constraint with the tangent circle?

working on master sketch of lesson 4, I find that if I delete the coincident constraint on the endpoint of the line, that point becomes blue ... adding the coincident constraint back onto the line endpoint to be coincident with the circle (already with an existing tangent constraint between line and circle) ... and now the endpoint is again black (full defined)

NeilCooke

Yes, because sometimes you may want a tangent line to a circle that isn’t coincident with it. 

KatieHuffman

Yes, to add one to what Neil said, the definition of tangency is line or arc crosses another circle/arc at exactly one point. That one point does not have to be the endpoint of the line. As an example, this line is tangent to the circle, but the endpoint is not coincident.

NeilCooke

Yes, because sometimes you may want a tangent line to a circle that isn’t coincident with it. 

KatieHuffman

Yes, to add one to what Neil said, the definition of tangency is line or arc crosses another circle/arc at exactly one point. That one point does not have to be the endpoint of the line. As an example, this line is tangent to the circle, but the endpoint is not coincident.