ABC26GN4760 · Volume and Surface Area

Subject: General Aptitude · Chapter: Volume and Surface Area · Exam: · Marks: · Difficulty:

Find the slant height, volume, curved surface area and the whole surface area of a cone of radius 21 cm and height 28 cm.
Answer
Answer (as printed):
Explanation
Here, r = 21 cm and h = 28 cm. ∴ Slant height, l = r 2 + h2 = (21)2 + (28)2 = 1225 = 35 cm. 1 2  1 22  Volume = πr h =  × × 21 × 21 × 28 cm 3 = 12936 cm 3 . 3 3 7   22  Curved surface area = πrl =  × 21 × 35 cm 2 = 2310 cm 2 .  7  2  22  Total surface area = (πrl + πr ) =  2310 + × 21 × 21 cm 2 = 3696 cm 2 .  7 

Explanation as extracted from the printed page; notation may be imperfect.

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