Given:
The vertices of the garden on a coordinate grid are (−1,5), (4,2) and (9,−4).
Each unit on the grid represents a foot and the material costs $8 per foot.
To find:
The cost for the material on the side between points (−1,5) and (4,2).
Solution:
Distance formula:

Using the above formula, the distance between points (−1,5) and (4,2) is



On further simplification, we get



Now,
1 unit = 1 foot and 1 foot material costs is $8.
So, 1 unit material cost is $8.
Cost of material for 5.83 units is

Therefore, the cost for the material on the side between points (−1,5) and (4,2) is $46.64.