Question

If the sides of a triangle are 3 cm, 4 cm and 6 cm long, determine whether the triangle is a right-angled triangle.

Answer 1

let $a$ = 3 cm; $b$ = 4 cm; $c$ = 6 cm

Now, $c^2=6^2=36$
$a^2+b^2=32+42$
$=9+16=25$

Since $c^2\ne a^2+b^2$, hence given sides are not of a right angled $\delta$.We know that in a right $\delta$, square of the longest side (hypotenuse) is equal to sum of the squares of other 2 sides.