Question 55910
slope of line through (2,3)(11,6) is
(6-3)/(11-2)=3/9=1/3
slope of line through (2,3)(-3,18) is
(18-3)/(-3-2)=15/-5=-3
therefore the line with a slope of -3 is perpendicular to the line with a slope of 1/3 (-3 is the negative reciprical of 1/3).