Question

The height and radius of a solid cylinder are 15cm and 3 cm respectively two equal cones each of radius 3cm and height 4 cm are cut off one from each circular end of the cylinder find the surface area of remaining solid

Answer 1

Answer:

The area of the remaining solid = 282.6 + 94.2 = 376.80 cm²

Step-by-step explanation:

Both the cylinder and the cones have the same radius.

So, what's left when the cones are cut out is the curved surface area of the cones.

The area of the cylinder will be the curved surface area of the cones plus the curved surface area of the cylinder.

The curved surface area of the cone = πrl

l = slant = √(h² + r²) = √25 = 5 cm

The curved surface area = 5 × 3 × 3.14 = 47.1 cm²

We have two cones so the total area of the conical parts = 2 × 47.1 = 94.2 cm²

The curved surface area of the cylindrical part is:

= 2πrh = 2 × 3.14 × 3 × 15 = 282.6 cm²

The area of the remaining solid = 282.6 + 94.2 = 376.80 cm²

Answer 2

Answer:

Step-by-step explanation: