Question

The sides of certain triangles are given below. Determine which of them are right triangles.

a = 1.6 cm, b = 3.8 cm and c = 4 cm

Answer 1

Given: a = 1.6 cm, b = 3.8 cm, c = 4 cm.

Largest side is c = 4, so check Pythagoras: c² = 4² = 16.

a² + b² = (1.6)² + (3.8)²

= 2.56 + 14.44

= 17.00 

Since a² + b² = 17.00 ≠ c² = 16, the Pythagorean relation does not hold.

The triangle with sides 1.6 cm, 3.8 cm, 4 cm is not a right triangle in fact, because a² + b² > c², the angle opposite the side of length 4 cm is acute.