Question

In the adjoining figure AB=AC and BD=DC. Prove that triangle ADB is congruent to triangle ABC and hence show that angle ADB = angle ADC=90°

Answer 1

Given:AB=AC

BD=CD

To prove that: ADB congruent to ADC

We have,

AB=AC(given)

BD=CD(given)

AD(common side)

Therefore, ADB ~ ADC (by SSS)

Also angle ADB =angle ADC (by c.p.c.t.)

But angleADB + angleADC = 180° (linear pair)

Implies that 2×angleADC = 180°

Implies that angleADC= 180°/2 = 90° = angle ADB

Hence, angleADC = angle ADB (Proved)

Answer 2

Answer:

ADB=90°

Step-by-step explanation:

given AB=Ac BD=DA.