Question

ABC is an isosceles triangle right angled at C. Prove that AB² = 2AC² 

Answer 1

Given that ΔABC is an isosceles triangle.

∴ AC = CB

Applying Pythagoras theorem in ΔABC (i.e., right-angled at point C), we obtain

AC² + CB² = AB²

=> AC²+ AC² = AB²   (AC = CB)

⇒ 2AC² = AB²