What is 0.42D in the cutting length calculation of crank bars?

In this video, I have shown the derivation of 0.42D in the crank bar formula, and the real reason for taking 0.42D instead of 1.42D in the crank bar cutting length calculation. To understand the 0.42D in detail you can visit the URL https://www.paramvisions.com/2021/01/what-is-042d-in-crank-bar-bent-up-bar.html My website link for civil construction knowledge is https://www.paramvisions.com/