IOS line measurement on picture

I need some help to get started on drawing lines with circle at ends, and measure its length. I am able to draw the line but can't make it moving,having spent hours decided to post on SO.

So please see below image and guide me to get started. Any sample or tutorial using objective c will help.

EDIT: The answer posted by ndmeiri is making use of multi touch. It is really great but unfortunately this has to be achieved without making use of multi touch. The scenario is, at any given time there will be some flexible lines available on screen. User can just drag any end point to resize the line in any direction. I can't get this thing working correctly..

Here is my gist file, code allows me to resize the line with touch points but doesn't allow to change the angle of line and adding text in centre. http://ift.tt/1dp9Hm0

Any help is highly appreciated. Thanks :)