The volume of the cylinder is 27. Find the diameter of the base of the cylinder if its total surface area

The volume of the cylinder is 27. Find the diameter of the base of the cylinder if its total surface area is 2 times the lateral surface area.

The volume of the cylinder is: V = Sсн * h = π * R ^ 2 * h.

The area of the lateral surface of the cylinder is: Sside = 2 * π * R * h cm2.

The total surface area of the cylinder is equal to: Sпов = Sbok + 2 * Sсн = 2 * π * R * h + 2 * π * R ^ 2 = 2 * π * R * (h + π * R).

By condition: Spov / Sbok = 2.

2 * π * R * (h + R) / 2 * π * R * h = 2.

(h + R) / h = 2.

h = R.

V = 27 * π = π * R ^ 2 * h = π * R ^ 3.

R ^ 3 = 27.

R = 3 cm.

D = 2 * R = 6 cm.

Answer: c) The base diameter is 6 cm.



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