Circle geo: common tangent (1 Viewer)

[hscishard]

Fitzpatrick: 20c Q16 and onwards.

What the hell do they mean by common tangent?
Aren't tangents like, continuous in this case?

I'll give an example.

Two circles of radii 5cm and 8cm touch each other externally. Calculate the common tangent.

Wtf isnt the tangent like the point where touches externally?

 

[SeCKSiiMiNh]

hmmm... i was under the impression that a common tangent is a one line which touches two circles.

 

[Flying_Penis]

= Penis

 

[SeCKSiiMiNh]

thats not funny no more =/^

 

[s2 SEductive]

It's just the same tangent of both circles

like this

http://asset1.learnhub.com/lesson/pages/14181/photos/28509-medium.jpg

 

[hscishard]

Yea the problem is, the middle one, it is impossible to calculate. It'll be like infinity.

But yea, I remember how to it now.

It's the tangent bounded by the one point of each circle.

 

[s2 SEductive]

Lol naww ty for the rep

 

[hscishard]

How do you notice you got repped so quickly?

I just notcied now that I'm on two bars

 

[s2 SEductive]

lol i told you im talented LMAO!!

have u figured out the answer ><
you know what's funny
i did this like 5 weeks ago , like my teacher just told me what to do
and i just remembered from then , but i haven't practiced it

 

[hscishard]

Yea it's 4 root 10.

The technique was to draw a rectangle, so you get a right angled triangle.
Then you use pythagoras and yea, just remember you're not finding the hypotenuse.

I got an exam on this when school starts

 

[s2 SEductive]

Yea it's 4 root 10.

The technique was to draw a rectangle, so you get a right angled triangle.
Then you use pythagoras and yea, just remember you're not finding the hypotenuse.

I got an exam on this when school starts

ooo i wanna learn this now