Pythagoras was an ancient Greek philosopher who found that mathematical equations could be applied to both musical tones and geometric shapes. Another Greek named Euclid discovered that he could divide a line into to parts so that the smaller line had the same ratio, or proportion, as the larger line had to the whole line. This was called the Golden Section or the Golden Mean. In math, this ratio is written 1 to 1.6. The Golden Rectangle has sides that matched this ratio.
Scale is similar to proportion, but is measured against a standard reference.
Exaggeration and distortion can accomplish expressive qualities in art. Variety Contrast and variety are important in art. If things are too much the same in a work of art it can become boring. Just as we may become bored if we see the same thing day after day in our lives, a work of art composed of the same colors and shapes becomes monotonous. Variety is the principle of art dealing with differences.