Angle that is smaller than a right angle (less than 90°).
right angle
Angle formed by two lines or two perpendicular planes that measures 90°.
perpendicular
Symbol denoting that a straight line meets another at a right angle.
is not parallel to
Symbol denoting that two straight lines do not remain at a constant distance from one other.
is parallel to
Symbol denoting that two straight lines remain at a constant distance from one another.
minute
Symbol placed in superscript after a number that denotes degrees in sixtieths of a measure.
second
Symbol placed in superscript after a number that denotes degrees in sixtieths of a minute.
pi
Constant that represents the ratio of a circle’s circumference to its diameter; its value is approximately 3.1416.
degree
Symbol placed in superscript after a number to denote the opening of an angle or the length of an arc, or in front of an uppercase letter to identify a scale of measurement.
