Question

Two cylinders of same radii $14$ cm, and heights $20$ cm, $25$ cm are placed one upon another then find the T.S.A (Total Surface Area) of the shape formed.

Answer 1

Letting the cylinders to be hollow.

Now the newly made cylinder has radius $\left(r\right)=14$ cm and height $\left(h\right)=20+25=45$ cm.

Now total surface are of newly formed hollow cylinder is $2\pi rh$ cm ${}^2=88\times 45=3960$ cm${}^2$.