Question 947296
Draw a square, side length 10 cm, and INSCRIBE a circle.  This circle and square touch in four points, and each of these points is the center of a side of the square.  The distance from one of these points to the point on an opposite side is ALSO 10 cm, and forms a diameter of the circle. 


The diameter of this circle is 10 cm.


You just need to draw a picture of the description to see this.