Define a perceptron that receives x and y as input and fires for these points:

a x $-$ b y $<=-$c

$1.$ weights: $-$a$,-$b$,$ threshold: $-$c

$2.$ weights: a$,$ b$,$ threshold: c

$3.$ weights: $-$a$,-$b$,$ threshold: c

$4.$ weights: $-$a$,$ b$,$ threshold: $-$c

$5.$ weights: a$,$ b$,$ threshold: $-$c

$6.$ weights: a$,-$b$,$ threshold: c

$7.$ weights: a$,-$b$,$ threshold: $-$c

$8.$ weights: $-$a$,$ b$,$ threshold: c