The height and the total surface area of a right circular cylinder are 4 cm and 8π sq.cm. respectively. The radius of the base of cylinder is
Show answer & explanation
Correct answer: A
Explanation
The correct answer is Option 1 i.e. (2√2 – 2) cm
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Understanding |
Application |
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The height and the total surface area of a right circular cylinder are 4 cm and 8π sq.cm. respectively. We know: Total surface area of cylinder = 2πr (r + h) |
So, 2πr(r + h) = 8π ⇒ r(r + 4) = 8 ⇒ r2 + 4r – 8 = 0 ⇒ r = [-4 + √(16 + 16)]/2 ⇒ r = [-4 + 4√2]/2 ⇒ r = (2√2 – 2) Hence, Radius of cylinder = (2√2 – 2) cm |