Question

Three side lengths are given in each of the following options. Choose the one in which a unique triangle can be constructed using SSS criterion.

• A. 3 cm, 6 cm and 3 cm
• B. 10 cm, 20 cm and 30 cm
• C. 20 cm, 5 cm and 40 cm
• D. 4 cm, 21 cm and 19 cm

Answer 1

The correct option is D 4 cm, 21 cm and 19 cm

To construct a unique triangle with the three sides given, sum of any two sides must be greater than the third side.

Hence,
Options a, b and c are incorrect because the sum of the two sides mentioned is not greater than the third side.

Therefore, option d is correct where sum of two sides is greater than the third side.

4 cm + 21 cm > 19 cm,
4 cm + 19 cm > 21 cm, and
19 cm + 21 cm > 4 cm.