The circumference of a circle is the distance around the circle. It is another name for the perimeter of a circle. The circumference of a circle is calculated using the formulae: \(\text{circumference ...

There are certain ACT and SAT questions that consistently stump students. The question below is a geometry question from the ACT that students often have a hard time solving. It asks you to find the ...

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 ...

So you have a circle. What is the area of that circle? Surely everyone remembers that the area of a circle is: Where Pi (π) is of course the number and r is the radius of the circle. Where does this ...