Table 2

Perimeters of four blade cross sections having the same area of π

Cross section shape

Perimeter

Triangle

= 8.080642

Rectangle

= 7.089816

Hexagon

= 6.597817

Circle

2π = 6.283186

Bai and Wang Nanoscale Research Letters 2011 6:240   doi:10.1186/1556-276X-6-240