Picture this circumstance occurring within a circle. The center of the circle is where all the blades meet. That means that in terms of a circle's parts, these blades are the radii of the circle. And if they are all evenly spaced out, and there are 3 of them, the central angle in between each pair is 120 degrees (360/3). Once we know that, we can use the arc length formula for a circle which is
[tex]AL=\frac{\theta}{360}*2\pi r[/tex] and filling in:
