Question

I need to make a triangle. One side is 12 feet and the other is 8 feet. Identify each value that could NOT be the length of the third side.

7 feet
12 feet
20 feet
23 feet
5 feet
19.9 feet
4 feet

Answer 1

Answer:

20 feet, 23 feet, 4 feet could NOT be the length of the third side ⇒ C, D, G

Step-by-step explanation:

In any triangle

• The length of each side should be greater than the difference of the lengths of the other two sides

• The sum of the lengths of any two sides greater than the length of the 3rd side

∵ One side is 12 feet and the other is 8 feet

→ Find their difference and sum

∵ Their difference = 12 - 8 = 4 feet

∵ Their sum = 12 + 8 = 20 feet

→ By using the rules above

∴ The length of the third side is between 4 feet and 20 feet

∴ 4 < third side < 20

∵ 7 feet, 12 feet, 5 feet, 19.9 feet are between 4 feet and 20 feet

∴ 7 feet, 12 feet, 5 feet, 19.9 feet could be the length of the third side

∵ 20 feet, 23 feet, 4 feet are not between 4 feet and 20 feet

∴ 20 feet, 23 feet, and 4 feet could NOT be the length of the third side