A.) Finding Surface Area of a Cylinder
Steps:
- Step 1: Find area of each face
- Step 2: Add up areas from each face
Surface Area Calculation:
To find the surface area \( S \) of a cylinder, we use the formula:
\[ S = 2\pi r^2 + 2\pi rh \]
where:
- \( r \) is the radius of the base,
- \( h \) is the height of the cylinder.
Given:
- Height \( h = 9 \)
- Diameter = 6, therefore radius \( r = \frac{6}{2} = 3 \)
-
Calculate the area of the two circular bases: \[ \text{Area of bases} = 2\pi r^2 = 2\pi (3)^2 = 2\pi (9) = 18\pi \]
-
Calculate the lateral surface area: \[ \text{Lateral surface area} = 2\pi rh = 2\pi (3)(9) = 54\pi \]
-
Add the areas together: \[ S = 18\pi + 54\pi = 72\pi \]
Final Surface Area:
\[ \text{Surface Area} \approx 72 \times 3.14 \approx 226.08 \]
So, \[ \text{Surface Area} = 72\pi \text{ or approximately } 226.08 \]
B.) Finding Volume of a Cylinder
Steps:
- Step 1: Find area of the base
- Step 2: Multiply area of base (B) to height
Volume Calculation:
To find the volume \( V \) of a cylinder, we use the formula:
\[ V = B \times h \]
where \( B \) is the area of the base.
-
Calculate the area of the base: \[ B = \pi r^2 = \pi (3)^2 = 9\pi \]
-
Multiply the area of the base by the height: \[ V = B \times h = 9\pi \times 9 = 81\pi \]
Final Volume:
\[ \text{Volume} \approx 81 \times 3.14 \approx 254.34 \]
So, \[ \text{Volume} = 81\pi \text{ or approximately } 254.34 \]