Question

let abc be a triangle such that AB=(x-1)cm,AC=2√x cm, BC=(x+1)cm .then : A=90. B=90. C=90. D=none of these​

Answer 1

Answer:

(a) A =90

Step-by-step explanation:

Answer 2

The required "option A) ∠A 90°" is correct.

Step-by-step explanation:

Given by question,

AB = (x - 1)  cm, BC = (x + 1)  cm and AC = 2$\sqrt{x}$ cm

∴ BC > AB

By Pythagoras Theorem,

$AB^2+ AC^2$

= $(x - 1)^2+(2\sqrt{x})^2$

= $x^2 + 1 - 2x + 4x$

= $x^2$ + 1 + 2x

= $(x + 1)^2$

= $BC^2$

∴ $BC^2 = AB^2 + AC^2$

Here, BC is hypotenuse

In triangle ABC, ∠A is right angled triangle.

∴ ∠A = 90°

Thus, the required "option A) ∠A 90°" is correct.