By Fatskills Exam Guides Team — the exam nerds behind 28,500+ quizzes and 2.1M practice questions across 500+ global exams.
Angles are measured in degrees.
One degree (°) is of a complete rotation around a circle. - right angle measures exactly 90°. The box in the corner denotes a right angle. - acute angle measures greater than 0°, but less than 90°. - obtuse angle measures greater than 90°, but less than 180°. - straight angle measures exactly 180°. - complementary angles. Each is the other’s complement. - supplementary angles. Each is the other’s supplement. - Adjacent angles are two angles that have a common vertex and a common side, with no overlap. - Vertical angles are two nonadjacent angles formed by two intersecting lines. Tip: Two intersecting lines form four angles.
Vertical angles formed by two intersecting lines are congruent and thus have the same measure.
In the figure shown, a° = c° and b° = d°.
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