In ΔABC, ∠A is a right angle. The lengths of AC and BC are 9 cm and 15 cm respectively. Point D is on AB such that BD = 6 cm, what is the length of CD?
Answer & explanation
Correct answer: option 4
CD2 = AD2 + AC2
CD = \(\sqrt {36 + 81}\) = \(\sqrt {117}\)
=3\(\sqrt {13}\)