Question 7

The length of the rock wall that the worker still needs to complete is 138 feet.

The total perimeter of the triangular flower garden is 239 feet. Since the worker has already completed two sides of the wall, the length of the remaining side, which is the rock wall yet to be built, can be found by subtracting the lengths of the two completed sides from the total perimeter.

A) 101

This option suggests that only 101 feet remains to be completed. If this were the case, the total length of the two sides already completed would have to be 138 feet, which does not logically align with the total perimeter of 239 feet since 239 - 101 = 138.

B) 185

Choosing this option implies that 185 feet of the rock wall remains. This would mean that the two completed sides add up to only 54 feet (239 - 185), which is improbable for a triangular flower garden and does not fit with the perimeter requirement.

C) 54

If 54 feet of the rock wall remained, this means that the two completed sides would total 185 feet (239 - 54). However, this option does not fit the context of the question where the lengths of the sides need to be logically possible for a triangle.

D) 138

This is the correct answer, as it indicates that the worker still needs to complete 138 feet of the rock wall. Therefore, if the lengths of the two completed sides are added to this remaining length, they would total 239 feet, which aligns perfectly with the given perimeter of the garden.

Conclusion

The correct answer is definitively 138 feet because it accurately reflects the remaining length required to complete the rock wall based on the total perimeter of the garden. All other options fail to logically account for the lengths of the completed sides and do not adhere to the constraints of a triangular shape.