Legs

On the left is a drawing of legs, with the muscles exaggerated.  In real life, the muscles are not so defined and only a slight hint of the full muscle is visible. Like arms, legs will appear different depending on their position.  When in a squatting position, the muscles around the knees will become more visible as they bunch up against each other.  When the legs are straight, the muscles will not be as visible, but some lines will still show.  In a tiptoe position, the gastrocnemius, or upper calf muscle, will bunch up towards the knee, and the tendons around the ankle will be visible due to the straining.  Look at your own legs in different positions, and if possible, observe ballet dancers or figure skaters.