Currently the line tool in telestrator is a free-form line.

1) I'd like the ability to draw a traditional straight line between two points. Much like the square or circle drawing tools, I should click to set one end and then drag to set the end point.
2) I'd like the ability to measure an angle by providing three points. The first point is the beginning of a straight line, the second point is the end of the line (which completes Side 1) and the beginning of the angle to be measured. The third point is the end of the Side 2 line.

Here's an example from a mobile app with these capabilities: