Square Feet. The square foot is a unit of area used in the imperial and U.S. customary measurement systems. A square measurement is the two-dimensional derivative of a linear measure, so a square foot is defined as the area of a square with sides 1 ft in length.
http://wiki.answers.com/Q/How_long_is_a_black_rhino_pregnant_for. A Black Rhino is pregnant usually between 419 and 478 days, or 15 to 16 months. The mother will give birth to a single calf, weighing in on average 35 to 50 kg, (about 80 pounds). The calf will stay with it's mother anywhere from 2 to 3 yea...
Both African and Asian elephants have a pregnancy that approaches two yearsâ22 months, to be exact. This is the longest gestation period for any land animal, and one âof the longest for any animal on earth. Elephants produce one baby at a time, and the youngster weighs around 105 kilograms (230 pounds) at birth.