Question

Find the surface area of the cylinder formed by the net. Use 3.14 for π.

Answer 1

Answer:

138.16 square feet

Step-by-step explanation:

The surface area of the cylinder consists of one rectangle and two circles.

1. The radius of the circle is 4 ft, then the area of the circle is

$A_{circle}=\pi r^2 =\pi \cdot 4^2 =16\pi \ ft^2$

2. The width of the rectangle is 1.5 ft, the length of the rectangle is the circumference of the circle.

Find the circumference:

$C=2\pi r=2\pi \cdot 4=8\pi \ ft$

Hence,

$A_{rectangle}=1.5\cdot 8\pi =12\pi \ ft^2$

3. The surface area of the cylinder is

$SA=2A_{circle}+A_{rectangle}=\\ \\=2\cdot 16\pi +12\pi =32\pi +12\pi =44\pi \approx \\ \\\approx 44\cdot 3.14=138.16\ ft^2$