Question

Determine whether the triangle whose lengths of sides are 3cm,4cm, 5cm is a right-angled triangle.​

Answer 1

To know whether a triangle is right-angled, we must know about the Pythagorean theorem.

I.e, in a right triangle, altitude² + base² = hypotenuse²

GIVEN: Lengths of sides 3cm, 4cm, 5cm

So, we have to prove that 3² + 4² = 5²

Take LHS: 3² + 4²

--> 9 + 16

--> 25

Take RHS: 5²

--> 25

LHS = RHS = 25

∴ 3² + 4² = 5²

∴ The triangle is right angled.