Question

Pls help me to answer 4 th question

Answer 1

Step-by-step explanation:

$AB {}^{2} =BD {}^{2} +AD {}^{2} \\ 15 { }^{2} = BD {}^{2} + (12) {}^{2} \\ BD {}^{2} = 225 - 144 \\ BD {}^{2} = 81 \\ BD = 9 \\ \\ AC {}^{2} = AD {} ^{2} +DC {}^{2} \\ AC {}^{2} = 12 {}^{2} + 5 {}^{2} \\ AC {}^{2} = 144 + 25 \\ AC {}^{2} = 169 \\ AC = 13 \\ \\ \\ AB = 15 \: \: \: \: BC = 14 \: \: \: AC = 13 \\ \\ perimeter \: of \: ABC = 15 + 14 + 13 = 42cm$