Measured Life-drawing

I was in a very interesting life drawing session yesterday. 

We started by doing a 40 minute measured drawing, first our tutor explained to us how to measure. It is key that your easel is not obstructing your view, and that you stand at arm's length from it, so that when you take a measurement of you figure, you can move your arm and jot down on your paper, without changing your point of view or bending your arm. I was drawing in my sketchbook, so i ripped out a page and stuck it to a board on an easel. 

The standard way of measuring is to pick a unit of measurement on the figure, such as a head for example, and to use it to measure the rest of your model, height, width, arm's length etc. But something i learned yesterday is- how to measure angles, but not only angles of individual body parts, but rather the angles of their relationship to each other. For example, to measure what the human eye understands as "points-of-symmetry" on the body, such as shoulders, hips knees etc. Normally poses are asymmetrical, but our tendency is to draw what we know as symmetrical points on the body, as such. Therefore a drawing starts to look inaccurate, so measuring the angle relationship of such points helps us depict the pose more accurately.  Which becomes even more useful when foreshortening occurs, where a measured drawing is key to accuracy, because our brains have a natural tendency for compensation of foreshortening, in order to recognize what we are actually seeing. Instead of drawing a foreshortened leg, we draw what we think a leg should look like, and a measured drawing forces our eyes to draw what we see not what we THINK we see. 

Below is an example of the two drawings i did, in yesterday's session, the first in pencil and second in acrylic on canvas. I've also included an explanation drawing of all the measurements i took.