Question: ABC is a triangle right angled at A and a perpendicular AD is drawn on the hypotenuse BC. The value of $ BC\cdot AD $ is equal to
Options:
A) $ AB\cdot AC $
B) $ AB\cdot AD $
C) $ CA\cdot CD $
D) $ AD\cdot DB $
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Answer:
Correct Answer: A
Solution:
- In case of a right angled triangle, if we draw a perpendicular from the vertex containing right angle to the hypotenuse, we get three triangles, two smaller and one original and these three triangles are similar triangles.
So, $ \Delta ABC\sim \Delta DBA\sim \Delta DAC $
$ \frac{BC}{AB}=\frac{AC}{AD} $
$ \therefore $ $ BC\cdot AD=AB\cdot AC $