Which of the following statements about perpendicular lines is true? a) perpendicular lines have a constant distance between them. b) perpendicular lines intercept at a 90 degree angle. c) there is no standard symbol for perpendicular lines. d) perpendicular lines do not exist in the same place.

Arefrigeration system at your company uses temperature sensors fixed to read celsius (°c) values, but the system operators in your control room understand only the fahrenheit scale. you have been asked to make a fahrenheit (°f) label for the high temperature alarm, which is set to ring whenever the system temperature rises above –10°c. what fahrenheit value should you write on the label?