Given a triangle with perimeter 63 cm, one side of which is 21 cm, and one of the medians is perpendicular to one of its angle bisectors. Find the lengths of all sides of the triangle. *The answer is not 21, 21, and 21

Hillary is using the figure shown below to prove pythagorean theorem using triangle similarity: in the given triangle abc, angle a is 90° 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? (6 points) by the addition property of equality, ac2 plus ad2 = ab multiplied by dc plus ad2. by the addition property of equality, ac2 plus ad2 = bc multiplied by dc plus ad2. by the addition property of equality, ac2 plus ab2 = ab multiplied by dc plus ab2. by the addition property of equality, ac2 plus ab2 = bc multiplied by dc plus ab2.