Question

Plz solve this
ans = 4400​

Answer 1

The total surface area of the solid is 4651 sq cm

Explanation:

Given,

The diameter of the base = 16 cm

Length of the cylindrical part (h) = 75 cm

The height of the solid = 90 cm

So, the radius of the base(r) =
`(16)/(2)` cm = 8 cm

The height of the cone = 90 - 75 cm = 15 cm

The slanting height(l) of the cone =
`\sqrt{15^(2)+8^(2) }` cm = 17 cm [ by Pythagoras theorem]

To find the total surface area of the solid

The solid consists of two separate solids that are a cylinder and a cone.

So, total surface area (TSA) of the solid = TSA of cylinder + TSA of cone

To find the TSA pf cylinder

Formula

TSA of cylinder = 2πrh +2πr

=2πr(r+h)

=2 ×
`(22)/(7)`×8×(8+75) sq cm

= 4173.7 sq cm (approx)

Again,

To find the TSA pf cone

Formula

TSA of cone = πrl +2πr

=πr(l+2) sq cm

=
`(22)/(7)`×8×(17+2) sq cm

= 477.7 sq cm (approx)

Hence, total surface area (TSA) of the solid = 4173.7 sq cm + 477.7 sq cm

= 4651.4 sq cm