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