Triangle ABC is right angled at B and D is a point of BC such that BD = 5 cm, AD = 13 cm and AC = 37 cm. then find the length of DC in cm.
Answer & explanation
Correct answer: option 2

Here, \(\Delta \)ABD is also a right angled triangle.
So,
\( { AB}^{2 } \) + \( { BD}^{2 } \) = \( { AD}^{2 } \)
= \( { AB}^{2 } \) = 169 - 25
= AB = 12
we know,
\( { AB}^{2 } \) + \( { BC}^{2 } \) = \( { AC}^{2 } \)
= \( { BC}^{2 } \) = \( { AC}^{2 } \) - \( { AB}^{2 } \)
= \( { BC}^{2 } \) = \( { 37}^{2 } \) - \( { 12}^{2 } \)
= BC = 35
= BD + DC = 35
= DC = 30
Therefore, DC is 30 cm.