From a solid cylinder whose height is 2.4 cm and diameter 1.4 cm, a conical cavity of the same height and same diameter is hollowed out. Find the total surface area of the remaining solid to the nearest cm2
Given:
Height (h) of the conical part = Height (h) of the cylindrical part = 2.4 cm
Diameter of the cylindrical part = 1.4 cm
Radius (r) of the cylindrical part = 0.7 cm
Slant height of the cylindrical part (l) = 
= 
= 
= 2.5
Total surface area of the remaining solid will be
= CSA of cylindrical part + CSA of conical part + Area of cylindrical base
= 2πrh + πrl + πr2
= 2 * 
* 0.7 * 2.4 + 
* 0.7 * 2.5 + 
* 0.7 * 0.7
= 4.4 * 2.4 + 2.2 * 2.5 + 2.2 * 0.7
= 10.56 + 5.50 + 1.54
= 17.60 cm2
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