Question

why triangle formed will given length will be a right angled triangle ∆ of sides 3cm ,4cm ,5cm

Answer 1

according to the Pythagoras theorem
if ABC is a right angled triangle and AB is the hypotenuse then

ABsq. = BC sq. + AC sq.

now, here
3 sq. + 4sq.
= 25

and 5 sq. = 25
so, it is a right angled triangle.

Answer 2

$because \: {3}^{2} + {4}^{2} equal \: {5}^{2} \: so \: according \: to \: pithagoras \: theorm \: this \: triangle \: is \: a \: right \: angle \: triangle$