tangent line to circle

[kwee]

how to do the followings:
1. a circle and a point P outside the circle, how to construct a
tangent fr P to the circle, so that i can drag the point P and the
tangent line move accordingly.
2. how to draw a tangent to 2 circles of different radii?
ty!

[John Hanna]

I used to know how to do that!

Let me Google that for you...
http://lmgtfy.com/?q=construct+a+tangent+to+a+circle+from+an+external+point&
l=1


John Hanna
jeh...@optonline.net
www.johnhanna.us
T3 - Teachers Teaching with Technology
"the future isn't what it used to be."

--
To post to this group, send email to tins...@googlegroups.com
To unsubscribe send email to tinspire+u...@googlegroups.com
For more options, visit this group at
http://groups.google.com.au/group/tinspire?hl=en-GB?hl=en-GB
The tns documents shared by group members are archived at
https://sites.google.com/site/tinspiregroup/classroom-news/welcome-abouttime

[Damion Beth]

Got it!

• Draw Circle with center A
• Place point P
• Draw segment from center of circle to point P
• Construct midpoint of segment AP, label X
• Draw circle X with radius XP
• Where Circle A and Circle P intersect, label it B
• Draw segment AB
• Draw segment PB
• Hide Circle X and any other stuff you don't want
• PB is now tangent to Circle A

You should be able to move point P wherever you want!

[kwee]

got it! also went to google for point 2 and i got it too. thanks
everyone!

On May 12, 6:19 am, Damion Beth <djb...@barabooschools.net> wrote:
> Got it!
>
>    - Draw Circle with center *A*
>    - Place point *P*
>    - Draw segment from center of circle to point *P*
>    - Construct midpoint of segment *AP*, label *X*
>    - Draw circle *X* with radius *XP*
>    - Where Circle *A* and Circle *P* intersect, label it *B*
>    - Draw segment *AB*
>    - Draw segment *PB*
>    - Hide Circle *X *and any other stuff you don't want
>    - *PB* is now tangent to Circle *A*
>
> You should be able to move point *P* wherever you want!

[Travis Bower at DPHS]

If you are not aware of this site, take a look. Fun tangent problem.

http://www.calculatorsoftware.co.uk/handheldgeometry/hg/hg104.htm

Sorry for the typos. I'm still learning to type on glass.