Post by kraj8995 on Aug 8, 2012 3:46:46 GMT -5
There are different types of angles.
An angle equal to 1/4 turn (90° or π/2 radians) is called a right angle.
Two lines that form a right angle are said to be perpendicular or orthogonal.
Angles equal to 1/2 turn (180° or two right angles) are called straight angles.
Angles equal to 1 turn (360° or four right angles) are called full angles.
Angles that are not right angles or a multiple of a right angle are called oblique angles.
Angles smaller than a right angle (less than 90°) are called acute angles ("acute" meaning "sharp").
Angles larger than a right angle and smaller than a straight angle (between 90° and 180°) are called obtuse angles ("obtuse" meaning "blunt").
Angles larger than a straight angle but less than 1 turn (between 180° and 360°) are called reflex angles.
Angles that have the same measure (i.e. the same magnitude) are said to be equal (UK) or congruent (USA). An angle is defined by its measure and is not dependent upon the lengths of the sides of the angle (e.g. all right angles are congruent).
Two angles opposite each other, formed by two intersecting straight lines that form an "X"-like shape, are called vertical angles or opposite angles or vertically opposite angles. These angles are equal in measure.
Angles that share a common vertex and edge but do not share any interior points are called adjacent angles.
Two angles that sum to one right angle (90°) are called complementary angles.
The difference between an angle and a right angle is termed the complement of the angle.
Two angles that sum to a straight angle (180°) are called supplementary angles.
An angle equal to 1/4 turn (90° or π/2 radians) is called a right angle.
Two lines that form a right angle are said to be perpendicular or orthogonal.
Angles equal to 1/2 turn (180° or two right angles) are called straight angles.
Angles equal to 1 turn (360° or four right angles) are called full angles.
Angles that are not right angles or a multiple of a right angle are called oblique angles.
Angles smaller than a right angle (less than 90°) are called acute angles ("acute" meaning "sharp").
Angles larger than a right angle and smaller than a straight angle (between 90° and 180°) are called obtuse angles ("obtuse" meaning "blunt").
Angles larger than a straight angle but less than 1 turn (between 180° and 360°) are called reflex angles.
Angles that have the same measure (i.e. the same magnitude) are said to be equal (UK) or congruent (USA). An angle is defined by its measure and is not dependent upon the lengths of the sides of the angle (e.g. all right angles are congruent).
Two angles opposite each other, formed by two intersecting straight lines that form an "X"-like shape, are called vertical angles or opposite angles or vertically opposite angles. These angles are equal in measure.
Angles that share a common vertex and edge but do not share any interior points are called adjacent angles.
Two angles that sum to one right angle (90°) are called complementary angles.
The difference between an angle and a right angle is termed the complement of the angle.
Two angles that sum to a straight angle (180°) are called supplementary angles.