Tangent line

[jcaz15]

Hi.

 

My question is:

 

Imagine you have drawn a circle, and at a specific location of its circunference, you want to construct a tangent line, How can I do it.

 

You can tried to "get" the exact tangent point, but that`s guessing.

 

Thank you a lot.

 

THANKS TO EVERYBODY WHO ANSWERS.

 

But the right answer is for the third person (eldon). Thank you a lot.

[alanjt]

draw the line from the center point of the circle to the outside of the circle (direction you want it drawn in) then just extend the line to where you want to go and trim it off on inside of circle. it will be tangent.

[rkent]

Hi.

 

My question is:

 

Imagine you have drawn a circle, and at a specific location of its circunference, you want to construct a tangent line, How can I do it.

 

You can tried to "get" the exact tangent point, but that`s guessing.

 

Thank you a lot.

 

Start the line command, pick a point away from the circle, use the TAN osnap, pick on the circle.

[eldon]

1. From the point P on the circle, draw a line to the centre of the circle.

 

2. Offset this line.

 

3. Draw a line between the ends of the lines. This is the required tangent

[dusko]

hello!

 

activate LINE or POLYLINE, enter TAN in command line and you can surf over circumference (in OSNAP drafting settings "tangent" must be selected).... (rkent, is this same thing that you wrote?)

 

[BIGAL]

Like eldon version 2 draw line from centre to point on circle then rotate line 90degs its tangential.

[Coosbaylumber]

Before there was Autocad I used have to calculate these things out by hand using common old geometry.

 

The distance from your Point One to center of circle must be figured out. Use coordinates for the distance.

 

You already know the radius.

 

Then using geometry, calculate the third side to the right triangle using squares. Or, Hypotenuse squared is equal to sum of other two sides squared and added together. ( A computer can do this in less than one second)

 

Set in a circle from Point One "exactly" the same radius as you calculated for the missing leg. Where it intercepts the known radius, is the same position as would fall a right triangle. And, perpendicular to the radial.

 

Accuracy will vary, as to how many places you extend the two unknown distance past a whole unit.

 

Did a lot of these calculations back when.

 

Wm.

[dpaulku]

Like eldon version 2 draw line from centre to point on circle then rotate line 90degs its tangential.

 

QFT this should be a no-brainer