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...
An Asian elephant is pregnant for 645 days while an African elephant is pregnant for 640 days. But it can be 21-23 months long. An elephant has the longest gestation period of any land animal, at 22 weeks. An elephant calf can weigh up to 260 pounds! An adult African elephant can weigh more than 15,000 pounds. http://answers.ask.com/Science/Other/how_long_are_elephants_pregnant_for. The gestation period of an average elephant is 22 months, or 630-660 days. The elephant has the longest gestation period of any mammal.