Question

From a solid cylinder of height 2.8 cm and diameter 4.2 cm, a conical cavity of the same height and same diameter is hollowed out. Find the total surface area of the remaining solid.(Take π=22/7) .

Answer 1

Step-by-step explanation:

take help from the attachment

Answer 2

TSA of the remaining solid = 73.92 sq.cm

Step-by-step explanation:

Height of cone = height of cylinder = 2.8cm

Radius of cone = radius of cylinder = 4.2/2 = 2.1 cm

slant height of cone = root of (2.8² + 2.1²) = root (7.84 + 4.41) = root 12.25 = 3.5cm

Curved Surface area of cone = πrl = 22/7 * 2.1 * 3.5 = 23.1 sq.cm.

CSA of cylinder = 2πrh = 2 * 22/7 * 2.1 * 2.8 = 36.96 sq.cm.

Area of cylinder top = πr² = 22/7 * 2.1 * 2.1 = 13.86 sq.cm

TSA of the remaining solid = 23.1 + 36.96 + 13.86 = 73.92 sq.cm