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October 8th, 2017, 03:08 AM  #1 
Senior Member Joined: Jun 2017 From: Lima, Peru Posts: 114 Thanks: 2 Math Focus: Calculus  How do you find the perimeter of a triangle inside these circles?
I am trying to solve this problem but I can't. It states like this: In this figure T, P are tangential points A, B and C are the center of each circle. Note that the circles are not in scale. What is the perimeter of the triangle ABC if the distance between AC is 7 centimeters?. I would appreciate that if the answer can include a better sketch of the figure with labels, sides and angles so I can figure out what's going on. Now, what's special about a tangential point?. Is there any property that makes them singular over other points?. Thanks in advance. 
October 27th, 2017, 05:49 AM  #2 
Member Joined: Oct 2017 From: Japan Posts: 62 Thanks: 3 
The perimeter is AC+CP+PB+BA=AC+CP+AT which should be equal to 21. The fact that the points are tangential allows you to solve the problem.

October 27th, 2017, 10:30 AM  #3 
Math Team Joined: Oct 2011 From: Ottawa Ontario, Canada Posts: 14,597 Thanks: 1039 
Did you notice that the 2 large circles are EQUAL in size? Not that it matters much... 

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circles, find, inside, perimeter, triangle 
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