â¢ equilateral - all 3 sides are equal. 2) By the types of angles they have: â¢ acute triangle - all 3 angles are acute (less than 90Â°) â¢ right triangle - has one right angle (a right angle = 90Â°) â¢ obtuse triangle - has one obtuse angle (an obtuse angle is greater than 90Â° and less than 180Â°).
Over the last 30 years, the time frame for the carving of the Grand Canyon has gone full circle. Thirty years ago, most evolutionists believed the canyon was about 70 million years old. But that estimate changed as radioisotope dating was utilized to show the plateau to be much older than the canyon itself.
The Grand Canyon is 277 miles (446 km) long, up to 18 miles (29 km) wide and attains a depth of over a mile (6,093 feet or 1,857 meters).or thousands of years, the area has been continuously inhabited by Native Americans who built settlements within the canyon and its many caves. The Pueblo people considered the Grand Canyon (Ongtupqa in the Hopi language) a holy site, and made pilgrimages to it.