# Thread: Another tough Geometry Question ( Pythagoras and Circles and Tangents)

1. ## Another tough Geometry Question ( Pythagoras and Circles and Tangents)

Hi guys,
another tough problem thats giving me some trouble. I thought i might look to the geniuses on this forum for help. Anyway, i am attaching a picture, basically i have to find the radius of the circle using phythagoras. The smaller circle has a radius of 1cm and the angle between the tangents is 90 degress.

Hope you guys can help.
Thanks so much.

2. ## Re: Another tough Geometry Question ( Pythagoras and Circles and Tangents)

Since the angle between the tangents is 90 degrees, the figure you will obtain by joining the radii of the larger circle with the tangents will be a square and CJ will be the diagonal of the square. You know the formula for the diagonal of square= Square root 2 side. Use that to find out the radius and also deduct 2cm diameter of the smaller circle to find the radius and side of the square.

3. ## Re: Another tough Geometry Question ( Pythagoras and Circles and Tangents)

hmm. for some reason i didnt see that but unfortunately the problem isn't solved. The diagonal CJ has a smaller area beyond the smaller circle which is indetermined. so yeah basically, i will still be missing a little bit of it. Thanks anyway. hope you understand what i am trying to say

4. ## Re: Another tough Geometry Question ( Pythagoras and Circles and Tangents)

That was just a hint.You can figure out the solution from there.Set up equation defining the smaller radius in term of larger radius.You may draw perpendicular from the centre of smaller circle to the tangent.

Also can you give suggestions to my post :- A fundamental Question.

5. ## Re: Another tough Geometry Question ( Pythagoras and Circles and Tangents)

Yeah. i understand that was a hint but i just tried it and basically am going around in circles and don't what i am doing wrong. Sorry, if i am annoying but yeah, having a lot of trouble here. Geometry isnt that great for me. haha. anyway. and yeah course. ill have a look now.

6. ## Re: Another tough Geometry Question ( Pythagoras and Circles and Tangents)

Hi,
Here's a solution:

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