ABC is right-angled triangle where mABC = 90o. If m = 15 cm, m = 20 cm, and , intersecting at the point D, find m (in cm).
Show answer & explanation
Correct answer: B
Explanation
The correct answer is option 2 i.e. 12.
Pythagoras theorem, AC2 = AB2 + BC2
BD = (AB × BC)/AC
According to the given question,

In the above figure, usin Pythagoras theorem,
AC2 = AB2 + BC2
⇒ AC2 = 152 + 202
⇒ AC2 = 225 + 400
⇒ AC2 = 625
⇒ AC = 25 cm
Now, BD = (AB × BC)/AC
⇒ BD = (15 × 20)/25
⇒ BD = 12 cm