Question

20 circular plates of 1 cm thickness are placed one above the other to form a sid the radius of each circular plate 7 cm find the total surface area of the solid thus formed
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Answer 1

Answer:

Total surface area of the solid formed = 1,188 $cm^{2}$

Step-by-step explanation:

Solid formed is of cylindrical shape

Total surface area = Area of the Cylindrical surface + 2 x Circular Area of Base

= 2π x radius of circular plate x height of the Cylindrical shape formed + 2 x π x radius of the circular plate Squared

= 2π x radius of circular plate x (height of the Cylindrical shape formed + radius of circular plate)

$= 2 . \frac{22}{7} . 7 ( 20 times 1 + 7) cm^{2}$ = 44 x 27 $cm^{2}$ = 1,188 $cm^{2}$