John and Tyrone each go for a morning jog before work. John’s jogging pace is represented by the equation Y equals 5X where Y is the number of miles he jogs and X is the number of hours he jogs. Tyrone’s pace is given by the graph

You need to show the graph too, or else I can't help you.

check the picture below.

well, the angle at the vertex d is clearly not a right-angle, let's check for the one at the vertex f which does look like,   however if it's indeed, that means ef is perpendicular to df, in which case their slopes will be negative reciprocal of each other.

so the negative reciprocal of the slope of ef is 1, however the slope of df is not 1, is 1/2, so nope, they're not perpendicular lines.