Today I was working with a student calculating probabilities. One problem involved a square inscribed in a circle. What is the probability that a randomly placed dot will fall within the square?  To solve such a problem, we simply find the area of the square and divide it by the area of the circle.  Remember that the area of a square is given by A = s^2, there s is the length of the side.  The area of circle is given by A = Pi(r^2).  You can use the approximation 22/7 for Pi or 3.14 to make calculations easier.