P-paratheses (do any math that has parentheses around the numbers) y=(2x5)+25
E-exponents (do the exponents next) y=(2x5)+5^2
M-multiplying. (Basically everything is self explanatory from here to then cuz im lazy to list examples)
Just basically if you don't use PEMDAS, you'll get the wrong answer
To determine if a line is perpendicular to another, you must first determine the slope...
m = y1-y2/x1-x2
m of FK = 3-5/3-6 = -2/-3 = 2/3
m of FJ = 3-2/3-8 = 1/-5
m of FL = 3-0/3-5 = 3/-2
m of KJ = 5-2/6-8 = 3/-2
m of KL = 5-0/6-5 = 5
m of JL = 2-0/ 8-5 = 2/3
In order for two lines to be perpendicular, their slopes must be opposite reciprocals...
FK is perpendicular to FL
FK is perpendicular to KJ
JL is perpendicular to FL
JL is perpendicular to KJ
FJ is perpendicular to KL