Question

Which of the following combinations are not possible for a triangle?

I.Sides as 4 cm, 9 cm, 13 cm.

II.Two obtuse angles.

III.Two acute angles.

IV. Sides as 9 cm, 8 cm and 7 cm.

Answer 1

In any triangle, sum of any two sides must be greater than the third side. Similarly, in any triangle, the sum of all the angles is 180°.

Keeping these two points in mind, condition I is not possible because (9 + 4) cm is not greater than 13 cm. Also, condition II is not possible because any two obtuse angles will add to a value greater than 180. In a triangle, that is not possible. However, conditions III and IV are possible.