A triangle with sides 5 cm, 12 cm, and 13 cm is a:
Answer: C
We check if the sides satisfy the Pythagorean theorem (a² + b² = c²).
The longest side is 13 cm, so it would be the hypotenuse.
5² + 12² = 25 + 144 = 169.
13² = 169.
Since 5² + 12² = 13², the triangle is a right-angled triangle. This is a common Pythagorean triplet (5, 12, 13).