Soru 1
A right triangle has legs of length 3 cm and 4 cm. If it is rotated 360 degrees around the leg of length 4 cm, what is the volume of the cone formed?
- Doğru cevap
$12\pi$ cm$^3$
- B
$16\pi$ cm$^3$
- C
$20\pi$ cm$^3$
- D
$24\pi$ cm$^3$
- E
$32\pi$ cm$^3$
Çözüm
When rotated around the leg of length 4 cm, this leg becomes the height $h = 4$ cm, and the other leg becomes the radius $r = 3$ cm. The volume of a cone is given by $$V = \frac{1}{3} \pi r^2 h.$$ Substituting, $$V = \frac{1}{3} \pi (3)^2 (4) = \frac{1}{3} \pi \cdot 9 \cdot 4 = 12\pi \text{ cm}^3.$$