Right angle Right angle In geometry and trigonometry, a right angle is an angle of exactly 90° (degrees), corresponding to a quarter turn. If a ray is placed so that its endpoint is on a line and the adjacent angles are equal, then they are right angles. The term is a calque of Latin "angulus rectus"; here "rectus" means "upright", referring to the vertical perpendicular to a horizontal base line. Closely related and important geometrical concepts are perpendicular lines, meaning lines that form right angles at their point of intersection, and orthogonality, which is the property of forming right angles, usually applied
Type 90 Kyū-maru tank made Type 90 more challenging to operate outside Hokkaido. Some politicians therefore criticized the effectiveness of Type 90 due to difficulty in transportation. In fact, more than 65% of major bridges in Japan were still considered passable for Type 90 while overseas main battle tanks such as Challenger 2 and Leopard 2 could only use 40% of bridges in Japan. Type 90 Kyū-maru The is a main battle tank (MBT) of the Japan Ground Self-Defense Force (JGSDF). It was designed and built by Mitsubishi Heavy Industries as a replacement for all deployed Type 61 and Type 74 tanks, and