Answer to Question #161839 in Geometry for cathy

Question

A software designer is mapping the streets for a new racing game. All of the streets are depicted as either perpendicular or parallel lines. The equation of the lane passing through A and B is -7x + 3y = -21.5. What is the equation of the central street PQ?

Answer 1

if the lane AB is parallel to the central street, then the central street has an equation -7x + 3y = c;

where c is the point of intercept on the next perpendicular street

However, if the lane AB is perpendicular to the central street, then the central street has an equation 3x + 7y = -c;

where c is the point of intercept on the next perpendicular street.