Why must one side be zero when solving equations by factoring.

i think it is 70

step-by-step explanation:

to find the perimeter, you add up all the lengths of the sides. in this case you would have to add up 18+22+40+80 which equals 160.

dont't really have enough info here but its likely

sss for the three sides being congruent ( its stands for side side side)

or

sas   for side angle side.   so a side is congruent and and angle and a side