Right angle of what a right angle is, namely two straight lines intersecting to form two equal and adjacent angles. The straight lines which form right angles are called perpendicular. Euclid uses right angles in definitions 11 and 12 to define acute angles (those smaller than a right angle) and obtuse angles (those greater than a right angle). Two angles are called complementary if their sum is a right angle. Book 1 Postulate 4 states that all right angles are equal, which allows Euclid to use a right angle as a unit to measure other angles with. Euclid's commentator Proclus gave a
Backstreet Boys: Larger Than Life making it the most attended residency in Las Vegas in terms of average audience. Encore: Clips from BACKSTREET BOYS – SHOW 'EM WHAT YOU'RE MADE OF feature film (c) Pulse Films/K Bahn LLC 2015 and BSB personal archives Special Thanks: Notes Backstreet Boys: Larger Than Life Backstreet Boys: Larger Than Life is the first concert residency by American vocal group Backstreet Boys, performed at Zappos Theater (formerly The AXIS Theater) in the Planet Hollywood Resort & Casino in Las Vegas, Nevada. The show had its opening night on March 1, 2017 and is scheduled to close on April 27, 2019