The isosceles triangle has a perimeter of 7.5 m.

which equation can be used to find the value of x if the shortest side, y, measures 2.1 m?

a.2x – 2.1 = 7.5
b.4.2 + y = 7.5
c.y – 4.2 = 7.5
d.2.1 + 2x = 7.5

4.63 cubic yard.

Step-by-step explanation:

Given,

The length of sidewalk, l = 100 feet,

Width, w = 5 feet,

Depth, h = 3 inches = 0.25 feet,

Thus, the volume of the concrete needed for making the sidewalk,

= 125 cubic feet,

∵ 1 cubic yard = 27 cubic feet,

⇒ 1 cubic feet = cubic yard,

Thus, the quantity of concrete needed = ≈ 4.63 cubic yard.