Hemisphere is the exact half of a sphere. When a plane cuts across a sphere at its center, it forms two hemispheres. Surface area of a hemisphere of radius r is given by 2pr2. Volume of a hemisphere of radius r is given by 2/3pr3.
Falling dreams also often reflect a sense of failure or inferiority in some circumstance or situation. It may be the fear of failing in your job/school, loss of status, or failure in love. You feel shameful and a lost sense of self-esteem You are unable to keep up with the status quo and feel that you don't measure up.
Quite like being chased, dreaming of falling indicates you have feelings of insecurity and anxiety in waking life. You could feel out of control in a waking life situation, it could be in a relationship, work situation or just in your general approach to life. Similarly these dreams could indicate that you are indulging in some form of self-destructive patterns of behaviour.