### Brain Teasers

# Circle

Imagine a square, with each side 4 cm long, inscribed in a circle. What is the radius of the circle?

### Answer

Since each corner is touching the circle, find the hypotenuse using the Pythagorean Theorem:4^2 + 4^2 = x^2

x = Hypotenuse = 5.657

Divide by 2 to get the radius:

Radius = 2.828

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