Answer:
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.
Step-by-step explanation:
Area=23ft²
Side=√23ft²
Side=4.8ft
For any sort of pyramid or cone, the volume is 1/3 of the volume of a prism with the same base and height. Since the volume of a prism/cylinder is

, the volume of a pyramid/cone is

.
In this case, our base is a circle, which has a radius of 4 cm.
The area of a circle is

where r is the radius.

We now know that our base is 16π cm.
We also know that our height is 9 cm.
Let's plug these into our volume formula.

Use 3.14 to approximate pi as the question states. 16 × 3.14 = 50.24.

We could punch all of that into our calculator to get the same answer, but since 1/3 of 9 is clearly 3, let's just go with that.

A^2+b^2=c^2
5^2+b^2=12^2
25+b^2=144
b^2=144-25
b^2=119
SQUARE ROOT BOTH SIDES:
b=10.9
The answer is c.