Geometry and Trigonometry practice question

Answer: C. 90π

V = πr²h = π(3²)(10) = π(9)(10) = 90π. Choice D (300π) squares the height by mistake or uses r = 10; square the radius, not the height.

Why the other answers are wrong

A. 30π

You multiplied r × h (3 × 10) without squaring the radius; the formula needs r² = 9, giving 90π.

B. 60π

2 × 3 × 10 = 60 is the lateral surface area formula 2πrh, not the volume; volume needs r², so π(9)(10) = 90π.

D. 300π

You squared the height instead of the radius: π(10²)(3) = 300π. Square the radius: π(3²)(10) = 90π.

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