To find the radius of a cylindrical can when given the diameter, you should divide the diameter by 2.
From your options, you need to first determine which measurement represents the diameter. Assuming that 3 and three fourths inches (3.75 inches) refers to the height of the can and 4 and one fourth inches (4.25 inches) refers to the diameter of the can, you would need to select the appropriate option.
Given:
- Diameter = 4 and one fourth inches = 4.25 inches
To find the radius:
- Radius = Diameter ÷ 2
Thus, you would perform the following step: B. Divide 4 and one fourth by 2.
Now, the radius would be: \[ \text{Radius} = 4.25 \div 2 = 2.125 \text{ inches} \]
Next, to find the surface area of the can, you can use the formula for the surface area of a cylinder, which is:
\[ \text{Surface Area} = 2\pi r(h + r) \]
where:
- \( r \) is the radius,
- \( h \) is the height,
- \( \pi \) is approximately 3.14.
Substituting the values:
- \( r = 2.125 \) inches,
- \( h = 3.75 \) inches:
\[ \text{Surface Area} = 2 \times 3.14 \times 2.125 \times (3.75 + 2.125) \]
First calculate \( (3.75 + 2.125) \): \[ 3.75 + 2.125 = 5.875 \]
Now calculate the surface area: \[ \text{Surface Area} = 2 \times 3.14 \times 2.125 \times 5.875 \]
Calculating step-by-step:
- \( 2 \times 2.125 = 4.25 \)
- \( 4.25 \times 5.875 = 24.9375 \)
- \( 24.9375 \times 3.14 \approx 78.21875 \)
Thus, the surface area of the can is approximately \( 78.22 \) square inches (rounded to two decimal places).