RE: this video ::::>
How to Build a Simple Cold Frame Hoop House
Gardening Videos from - Backyard Gardener
As I am sure most of you know the "higher math" the cold frame builder used was wrong. He said C= pi x R squared. It was an accident of the radius dimension "2" that he arrived at his approx. correct answer. Use his equation, with a radius of 5 and see what happens.
Circle Circum = 2 x Radius x pi(3.14).