Question

AB=AC , Suppose D is the mid point of BC.Prove that AD is perpendicular to BC

Answer 1

Answer:

Between ∆ABD and ∆ADC

AB=AC

BD=CD

AD is common side

∆ABD and ∆ADC are congruent (S-S-S)

So, angle ADB = angle ADC.

Since, <ADB + <ADC = 180°

=> <ADB = 90°=<ADC

hence AD perpendicular to BC