To find the volume of a cylinder, the first step is to determine the radius from the diameter. The diameter is given as 7 yards, so the radius \( r \) is half of the diameter. Therefore, the correct answer to Part 1 is:
D. Use the diameter to find the radius of the cylinder.
Part 2: Finding the Volume of the Cylinder
The formula for the volume \( V \) of a cylinder is given by the equation:
\[ V = \pi r^2 h \]
Where:
- \( r \) is the radius
- \( h \) is the height
-
Calculate the radius: \[ r = \frac{diameter}{2} = \frac{7 , \text{yd}}{2} = 3.5 , \text{yd} \]
-
Plug the radius and height into the volume formula: \[ V = \pi (3.5 , \text{yd})^2 (12 , \text{yd}) \]
-
Calculate \( (3.5)^2 \): \[ (3.5)^2 = 12.25 \]
-
Now substitute back into the volume formula: \[ V = \pi (12.25) (12) \]
-
Multiply \( 12.25 \) by \( 12 \): \[ 12.25 \times 12 = 147 \]
So, the volume of the cylinder is: \[ V = 147\pi , \text{yd}^3 \]
Thus, the volume of the cylinder is: \[ \text{Volume} = 147\pi , \text{yd}^3 \]
This is your final answer for Part 2.