SOLUTION: four circles of radius 1 are inscribed in a larger circle. The large circle is tangent to every smaller circle. Each small circle is tangent to the large circle and to two small ci

Question 308572: four circles of radius 1 are inscribed in a larger circle. The large circle is tangent to every smaller circle. Each small circle is tangent to the large circle and to two small circles. What is the radius of the large circle?
Answer by Fombitz(32388) (Show Source): You can put this solution on YOUR website!
Look at just one quadrant.

As you can see from the diagram, the green line along with the two radii form a square of side, . The distance from the origin to the larger circle (the radius of the larger circle) is equal to the diagonal of the square (blue line) plus the radius of the small circle.

Since R=1, then,

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