Enter the circle’s radius in the indicated field and select the dimension unit. Optionally, you can use the diameter and perimeter – circumference to calculate the circle’s area. If we have a circle ...

Scientific American presents Math Dude by Quick & Dirty Tips. Scientific American and Quick & Dirty Tips are both Macmillan companies. Throughout history, circles have symbolized many things: unity, ...

STEP 1 - WRAP RIBBON: Take the ribbon and wrap it around a glass. Mark where the ribbon overlaps itself. Image caption, STEP 2 - CUT CIRCUMFERENCE: Cut the ribbon at the point where it overlaps. You ...

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 ...

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 ...