For the orthographic projection as a map projection, see Orthographic projection in cartography. For mathematical discussion in terms of linear algebra, see Projection (linear algebra).
Bullfrogs are the largest real frog found in North America, weighing up to 0.5 kg and measuring 460 mm in length. Their average length is 100-175 mm. Their color varies from brownish to shades of green, often with spots or blotches of a darker color around their backs. Their back feet are fully webbed.
The dorsal (upper) surface of the bullfrog has an olive-green basal color, either plain or with a mottling and banding of grayish-brown. The ventral (under) surface is off-white blotched with yellow or gray. There is often a marked contrast in color between the green upper lip and the pale lower lip.he bullfrog is harvested for use as food in North America and in several countries into which it has been introduced. It is also cultured in controlled environments, though this is a difficult and not always successful undertaking.