Move line into circles tangent

 

I hope you understand the problem explained in picture.

One way....

 

Draw a line PERP to the 51° line (in the NW direction in this case)

Make it's length = to the radius of the arc.

Move both lines.

Using the far endpoint of the new line as the base point, and move to the center point of the arc.

Erase new line, adjust the existing line for length. It is tangent.

copy the arc any distance at 51 degrees, draw tan to tan, erase the arc.

Another copy line rotate 90 then put 1 end on center of arc intersecting pt is tangent point.

Or draw a line from the Center of the red arc, perpendicular to the line.

 

Move the line from the Endpoint of the new line to the Intersection with the red arc.

Or draw a line from the Center of the red arc, perpendicular to the line.

 

Move the line from the Endpoint of the new line to the Intersection with the red arc.

 

Thanks i will use your solution

You can use parametrics, pick tangent, pick arc, pick line.

OP says the angle cannot change. If that is the only restriction, simply moving or copying the line by the midpoint grip to the tangent snap will do it.

 

We just had a nearly identical issue posted by another member yesterday, only they were having trouble finding the Tangent snap. D'y'all ever notice these things seem to come in bunches.

Why not another method UCS OB Ortho on Draw line from arc center past arc intersection point is tangent then UCS W.

OP says the angle cannot change. If that is the only restriction, simply moving or copying the line by the midpoint grip to the tangent snap will do it.

 

We just had a nearly identical issue posted by another member yesterday, only they were having trouble finding the Tangent snap. D'y'all ever notice these things seem to come in bunches.

 

That won't work here, and I suspect it doesn't work for others which is the reason for other solutions.

 

Parametric solution seems like the best to me, and quickest.

That won't work here, and I suspect it doesn't work for others which is the reason for other solutions.

 

Parametric solution seems like the best to me, and quickest.

It's against the laws of geometry for it not to work. If it isn't working then the line has crossed the curve and is intersecting at more than one point, or never got all the way to the curve.

 

EDIT: We are dealing with AutoCad, a tangent snap point and a line being moved by its mid-point grip, at least I am.

Edited May 23, 2015 by Dana W