Zoe is using the figure shown below to prove pythagorean theorem using triangle similarity: in the given triangle abc, angle a is 90o and segment ad is perpendicular to segment bc. the figure shows triangle abc with right angle at a and segment ad. point d is on side bc. which of these could be a step to prove that bc2 = ab2 + ac2? by distribution, ac2 plus ab2 = bc multiplied by the quantity dc plus ab. by distribution, ac2 plus ab2 = bc multiplied by the quantity dc plus bd. by distribution, ac2 plus ad2 = bc multiplied by the quantity dc plus ab. by distribution, ac2 plus ad2 = bc multiplied by the quantity dc plus bd.