You need to determine how much paper you need to cover the lateral side of the cylinder shown in the picture. For this, you have to calculate the surface area of the cylinder, which you can do using the following formula:

Where
A is the area
π is the number pi, for the calculations we usually use up to the first two decimal values of this number, 3.14
r is the radius
h is the height of the cylinder
The given cylinder has a height of h=15m and a diameter of d=6m
To calculate the lateral area you need to use the radius. The diameter is twice the radius, so to determine the radius of the cylinder you have to divide the diameter by 2

Now you can calculate the lateral area as follows:

Charlie will need 282.6 m² to cover the lateral side of the cylinder.
They are still parrallel lines
Adding together the shorter two sides results in 17 m. If these two sides were laid end to end, the sum of their sides (17 m) would be less than the length of the third side. Thus, NO triangle could be constructed with this set of line segments.
Answer:
A = 1/2 B H area = 1/2 base X height
B = 2 A / H = 2 * 99 / 12 = 16.5 cm
dA / d t = 1/2 * (B dH / dt + H dB / dt)
dB / dt = (2 dA / dt - B dH / dt) / H
dB / dt = (2 * 1.5 cm^2 / min - 16.5 cm * 2 cm / min) / 12 cm
dB / dt = (3 - 33) / 12 cm/min = -2.5 cm/min