Question

Which of the following sets of 3 side lengths could form a unique triangle?

O side lengths: 18 feet, 9 feet, 6 feet
O side lengths: 12 feet, 9 feet, 4 feet
O side lengths: 6 feet, 3 feet, 2 feet
O side lengths: 24 feet, 14 feet, 4 feet

Answer 1

side lengths: 12 feet, 9 feet, 4 feet

Explanation:

Conditions for unique triangles with 3 sides:

• The sum of the two shorter sides must be greater than the third side.

9 + 6 = 15

As 15 < 18 this is NOT a unique triangle

9 + 4 = 13

As 13 > 12 this IS a unique triangle

3 + 2 = 5

As 5 < 6 this is NOT a unique triangle

14 + 4 = 18

As 18 < 24 this is NOT a unique triangle