Question

In a triangle ABC , angle A=90, AB=5cm, AC=12cm and AD is perpendicular to BC find AD

Answer 1

Answer:

area of triangle = (1/2) × base×height

if we take AC as perpendicular then AB will be base.

then area of triangle = (1/2)× 5×12 = 30 cm²

also, by Pythagoras' theorem,  

BC² = AC² +AB²

      =12² + 5² = 169

⇒BC = 13 cm

now, if AD is perpendicular then BC is the base

area of triangle = (1/2)× BC ×AD

⇒30 = (1/2)× 13×AD

⇒AD = 60/13 =4.61 cm