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...
A white rhino's horns are slightly smaller, and a Sumatran rhinos horns are about 10 to 31 inches (25 to 79 cm) for the front and less than 3 inches (7 cm) for the rear. The greater one-horned rhino's horn is 8 to 24 inches (20 to 61 cm), and Javan rhinos have a horn that is about 10 inches (25 cm) long.ffspring. Every two and a half to five years, a female rhino will reproduce. Female rhinos carry their young for a gestation period of 15 to 16 months. They usually only have one baby at a time, though they do sometimes have twins.