A closed metal drum is a frustum with end radii 12 cm and 3 cm and a vertical height of 12 cm. Find its total surface area, in cm². (Take \π = 22/7 .)

Question

Accepted Answer

1188. l = √12^2 + 9^2 = √225 = 15 cm. TSA = \π l (R + r) + \π R^2 + \π r^2 = 22/7(15 × 15 + 144 + 9) = 22/7 × 378 = 1188 cm². 707.14 is the curved surface alone; 1159.71 adds only the big end and 735.43 only the small end - the drum is closed, so BOTH ends count.

A closed metal drum is a frustum with end radii 12 cm and 3 cm and a vertical height of 12 cm. Find its total surface area, in $cm^{2}$ . (Take $π = \frac{22}{7} .$ )

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More Class 10 Frustum of a Cone practice

A closed metal drum is a frustum with end radii 12 cm and 3 cm and a vertical height of 12 cm. Find its total surface area, in cm2. (Take π=722​.)

Step-by-Step Solution

Master this chapter in 30 minutes a day.

More Class 10 Frustum of a Cone practice

A closed metal drum is a frustum with end radii 12 cm and 3 cm and a vertical height of 12 cm. Find its total surface area, in $cm^{2}$ . (Take $π = \frac{22}{7} .$ )