Please refer attached part.

Here's a snapshot of Sketched Bend 1.

Here's a snapshot of the same in flatpattern,

I want to retrieve the two adjacent reference lines to the bend center line.

At what distance should they be from the bend center line?

Is there any formula for this calculation?

Here's what I want to calculate,

Formula for length of bend is L = R * Ang where L is the bend length, R equals the bend radius plus the thickness * K-factor, and Ang equals the bend angle in radians. Hope this is what you are looking for?