I need to create a simple drawing app. This app consists of a line with two anchor points, one at each end. The user should have the ability to touch down on an anchor point and drag it to manipulate the line's length and slope. Also the user should be able to touch down on the line connecting the two anchor points to move it and the anchor points around the screen.

I'm kind of stumped here, I know that I could probably do the manipulation of the length and slope by simply using touch down/up but I do not think this will work for multiple lines?! Can anyone point me in the direction I should be looking please? Many thanks :)