Creating a tangent circle in graphing.

[DeadlyToad]

I am trying to create a tangent circle on my calculator between two lines ( 90 degree angle). So I can see how well my radius will fit thanks.

[webmasterpdx]

There is an infinite number of solutions to this problem. If you draw a line that bisects the angle between the 2 lines, the center of the circle must lie on this line and it's radius will be the perpendicular distance to each line.....should be the same for both lines. This will give you an infinite number of circles with center along that bisecting line.

[webmasterpdx]

If you create a 3rd line, you can use the incircle function in the geometry app to create a circle that is a tangent to all 3 lines.....with the 3rd line there is only one solution.

[DeadlyToad]

Thanks that works perfect, one last question tho how can I make a line go at a certain angle.
Thanks

[webmasterpdx]

You could specify 2 points using polar coordinates and convert them to rectangular coordinates and draw the line through the 2 points.

[DeadlyToad]

Hmmm could you screenshot on how you did that.
Thanks

[webmasterpdx]

I didn't. It was just a recommendation....There are operators to convert between polar and rect coordinates. LOok those up and play around with it...

[webmasterpdx]

Lets say you want a line going through the origin at an angle of pi/2, then you'd enter the polar form, as 1<angle>(pi/2)
<angle> is shift-multiply
pi is shift-3

Then, you can just hit the angle key (shift-multiply) and it'll convert it into a complex number. You can then take the complex number as rectangular coordinates and 0,0 and draw a line between them....

...something like that :-)

[webmasterpdx]

I was curious how to do it so I tried it....here is how you'd do it.
Use the geometry app.
Create first funciton, GA, to be a point(1<angle>(pi/4))
Create second point, GB, to be point(0,0)
Then, create a line between them, GB, line(GA,GB)
....and there is your line at an angle of pi/4.

BTW, the best place to find stuff is the wiki...
http://www.wiki4hp.com/doku.php?id=prime:start

[webmasterpdx]

I just added a polar/rect page to the wiki that might interest you...
http://www.wiki4hp.com/doku.php?id=prime:polrec

[DeadlyToad]

Ok I am kinding understanding that I will keep messing with it more to get familiar with it.