Question

ABC. is an isoceles triangle and angle B =90°, then show that AC²=2AB²

Answer 1

Its very simple
A tri ABC has one angle 90 degrees
Let AC is the hypotenuse and AB =BC as the tri is isosceles.
According to pythagoras theorem
${ac}^{2} = {ab}^{2} + {bc}^{2} \\ {ac}^{2} = {ab}^{2} + {ab}^{2} \\ {ac}^{2} = 2 {ab}^{2}$
Hence Proved.