The radius of a circle or a sphere is the distance between the center and the edge. The radius can be used to calculate a circle's diameter, area and circumference. Likewise, a sphere's volume is ...

\(V = \frac{4}{3}\pi {r^3}\) where r is the radius. This can be done on a calculator by \(4 \div 3 \times \pi \times {6^3}\) , using the \(\pi\) or if you don’t have a scientific calculator, use 3.14) ...

View image: http://sdw.webhop.net/tmp/problem.jpg <BR><BR>I want to step through the 2D coordinates (x,y) in the above picture. Say for example that x=0...1 and y=0 ...