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.
Doctors and scientists aren't really sure why they happen, but they have a few theories. One theory is that your brain misunderstands the sensation of your muscles relaxing as you drift off to sleep. It's normal for the muscles to relax, but the brain gets confused, and, for a minute, thinks you're falling. In response, the brain causes your muscles to tense up so you catch yourself before you fall down.