Question

The lengths of two sides of a triangle are 12 cm and 15 cm. Between what two measures should the length of the third side fall?

Answer 1

In a triangle, the sum of the lengths of either two sides is always greater than the third side and also, the difference of the lengths of either two sides is always lesser than the third side. 
Here, the third side will be lesser than the sum of these two (i.e., \(12 + 15 = 27\)) and also, it will be greater than the difference of these two (i.e., 1\(5 - 12 = 3\)).

Therefore, those two measures are \(27\) \(cm\) and \(3\) \(cm\).