Dark Nation
04-06-2010, 11:19 AM
Here's one I ran across the other day.
http://i797.photobucket.com/albums/yy251/DarkNationAG/circles.gif
The radius of the red circle is 1. The radius of the green circle is 2. The 3 circles are tangent to each other and to the white semicircle. What's the radius of the blue circle? Explain your answer.
http://i797.photobucket.com/albums/yy251/DarkNationAG/circles2.gif
For extra credit, what's the radius of the purple circle, if it's tangent to the red, green, and blue ones?
http://i797.photobucket.com/albums/yy251/DarkNationAG/circles.gif
The radius of the red circle is 1. The radius of the green circle is 2. The 3 circles are tangent to each other and to the white semicircle. What's the radius of the blue circle? Explain your answer.
http://i797.photobucket.com/albums/yy251/DarkNationAG/circles2.gif
For extra credit, what's the radius of the purple circle, if it's tangent to the red, green, and blue ones?