What is the area (including the ends) of a cylinder diameter 10 cm and 10 cm in height?
- 50pi
- 100pi
- 150pi
Explanation
Total surface area is the curved side plus the two circular ends: pi*d*h + 2*pi*r^2. With diameter 10 cm (radius 5 cm) and height 10 cm, the side is pi*10*10 = 100pi and the two ends are 2*pi*5^2 = 50pi, giving 150pi square cm. The 100pi distractor omits the ends.
nasermahmud asking:
PLEASE EXPLAIN
Community Comments (1)
D
dimky Posts: 514 22.06.2012 / 19:04
5^2 * pi = top end area
5^2 * pi = bottom end area
10 * 10 * pi = side area
(25 + 25 + 100) * pi = total area
5^2 * pi = bottom end area
10 * 10 * pi = side area
(25 + 25 + 100) * pi = total area
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