Question

Lengths of two sides of a triangle are 12 cm and 15 cm. Then the length of the third side must be .

• A. > 5 cm & < 27 cm
• B. > 3 cm & < 27 cm
• C. > 5 cm & < 12 cm

Answer 1

The correct option is B > 3 cm & < 27 cm

Given, lengths of two sides of a triangle are 12 cm and 15 cm.
Let the length of the third side be L.
We know, the sum of the lengths of any two sides of a triangle is greater than the length of the third side.
So, (15 + 12) > L
i.e., L < 27 cm
Also, we know the difference between the lengths of any two sides is lesser than the length of the third side.
Hence, (15 - 12) < L
i.e., L > 3 cm