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# three circles

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Three circles of radius 1 are drawn, each tangent to each other.  Find the radius of the large circle. May 8, 2020

#1
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Sorry mate but I don't know how to help.

One thing you could do is:

- Draw an equilateral triangle in the middle (each point connecting to the centre of the small circles)

--> The length of the triangle sides would = 2

- Use this formula to find the distance from the vertices of the triangle to the centre:

--> https://www.quora.com/What-is-the-distance-between-the-centre-of-an-equilateral-triangle-and-any-of-its-vertices

- + 1 (length of the radius)

Hope this helps (pretty sure this is not the way to go about it but it logically works)..

:) <3

May 8, 2020
#2
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Three circles of radius 1 are drawn, each tangent to each other.  Find the radius of the large circle.  May 8, 2020
#3
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MN = MP = 1

Angle NMO is 30°

OM = MN / cos(30°)  = 1.154700538

OP = OM + MP = 2.154700538

The radius of a large circle    r = 2.154700538  May 8, 2020