Question

30 circular plates, each of radius 14cm and thickness 3cm are placed one above other to form a solid.Find the total surface area of the solid formed.
My book answer is 9152 sq cm

Answer 1

given,
radious(r) =14cm
thickness =3cm
Now total hight of the solid formed (h) is
30*3 =90cm
Now total srface area is
=2¶rh+2¶r²
=2¶r(r+h)
=2*(22/7)*14* (14+90)
=4*22*104
=9152cm²[Ans]