right angle

angle formed by the intersection of two perpendicular lines, 90 degree angle

In geometry and trigonometry, a right angle is an angle of 90 degrees, corresponding to a quarter turn (that is, a quarter of a full circle). It can be defined as the angle such that twice that angle amounts to a half turn, or 180° .Lines that are at a right angle to each other are perpendicular, an important geometrical property. The presence of a right angle in a triangle is the defining factor for right triangles.A right angle may be expressed in different units:90°π/2 radians100 grad (also called grade, gradian, or gon)8 points (of a 32-point compass rose)6 hours (astronomical hour angle)∞% grade on the tangent scale100% grade on the sine scale.
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Noun
1. the 90 degree angle between two perpendicular lines
(antonym) oblique angle
(hypernym) angle
2. a quarter of the circumference of a circle
(synonym) quadrant
(hypernym) angular unit
(part-holonym) straight angle
(part-meronym) degree, arcdegree

right-angle
danh từ góc vuông, góc 90 độ
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