Find the slope of the first line, that is the difference of the y’s over the difference of the x’s. This way: 2-5/2-5=-3/-3 which equals 1 Now find the slope of the second line 2-(-6)/-5-3 =8/-8 =-1 The slopes are opposite reciprocal ( you could also say that the product of the 2 slopes equals -1) therefore the lines are perpendicular.
