How to draw a circle so that a line becomes a tangent to it

[Surajit]

Hi

This is my first question to this esteemed forum. I want asolution from the forum for the following problem.

I’ve an already drawn inclined line from a fixed point (saypoint (0,2) on Y-axis). The inclination is also fixed (say 150 tothe horizontal). My objective is to draw a circle with one quadrant at a fixedpoint (say point (1,0) on X-axis), so that, the line becomes a perfect tangentto the circle. The diameter of the circle may vary to make the line perfecttangent to the circle. How can I do it?

Thanks in advance

Surajit

[Organic]

In AutoCad you can use the Circle -> tan tan radius option

[MSasu]

Can you please post a sketch of that case? I'm not able to understand it from your description - a line can be tangent on quadrant only to a horizontal or a vertical line, not a sloped one.

[MSasu]

Reading twice your requirements, is this the case you were looking for?

 

[MSasu]

If the above sketch is correct, then the formula of radius for the desired circle is:

Radius = Distance / (1 + Cosine(Angle))

where:

• Distance means the distance from the given point to the given line.
  
• Angle is the angle made by the given line with X axis.
  

 

 

If I will have time later, will try to write you a routine for this.

[Stefan BMR]

Perhaps one of these:

[Surajit]

Hi

Thanks for your replies. I'm sorry, I could not make you understand actually what I wanted. I'm enclosing an AutoCad drawing showing the sketch. The drawing is self explanatory.

I'm new to this forum. In attachment is not successful, kindly let me know.

 

Thanks

Surajit

Tangent to a circle.dwg

[dbroada]

ah, that's clearer.

 

One way (may not be the best)

draw a vertical line through your fixed point.

mirror your angled line

CIRCLE 3P

tangent to one sloping line

select fixed point

tangent to other sloping line

 

Done.

[neophoible]

So, it looks like Stefan's top version. Nice solution, Dave. It doesn't get much simpler than that!

[Surajit]

Oh. that's great and so easy. Thanks:)