Drag the slider "sides" to change the number of sides that the regular polygon has. Notice what numbers the area and the perimeter approach. Change the radius to see how the area involves the radius squared and the perimeter does not include it squared. Pi or π as a decimal is 3.14159.
Danielle Buhrman, Matt James Grand Island HS and Lincoln Southwest HS Grand Island, NE and Lincoln, NE mjames2@lps.org