Radius of a Dog

Let’s do a little math:

Given: I’m with my dog outside for his daily business. I’m holding a leash and pivoting about my own vertical center. The leash is 25′, and I add the length of my arm and half the width of my chest, about 3′.

The area of a circle formula is πr², which in English is PI (ratio of the circumference of a circle to its diameter, or about 3.14) times the radius (one half of the diameter) times the radius again.

In this case the dog has 3.14*28 feet *28 feet, or roughly 2,461 SQUARE FEET to sniff around in. That’s about 77 sheets of plywood in space!

Then why does he insist on leaving the circle to sniff what is just otherwise beyond his reach?