Question

from a solid right circular cylinder of height 2.4cm and radius 0.7cm, right circular cone of same height and same radius is cut out. Find the total surface area of the remaining solid​

Answer 1

Answer:

12.32sq.cm

Step-by-step explanation:

Total surface area= CSA Of cylinder + area of circular base + Inner CSA Of cone

$2\pi rh +\pi r {}^{2} + \pi \:rl$

Where,

$l = \sqrt{r {}^{2} + h {}^{2} }$

Answer 2

Given:-

• From a circular cylinder of height 2.4 cm and radius 0.7, right circular cone of same height and same radius is cut out.

To Find:-

• Total Surface Area of the remaining solid.

Solution:-

Let us first find the Total Surface Area of the Cylinder.

We know,

• Total Surface Area of cylinder = 2πr(r + h)

Hence,

TSA of cylinder = 2 × 22/7 × 0.7 (0.7 + 2.4)

= TSA = 2 × 22 × 0.1 × 3.1

= TSA = 13.64 cm²

∴ TSA of the cylinder is 13.64 cm².

Now,

We are given that the height and radius of a right circular cone is as same as cylinder. Hence, we need to find the slant height of the cone.

We know,

• l = √r² + h²

Hence,

l = √(0.7)² + (2.4)²

= l = √0.49 + 5.76

= l = √6.25

= l = 2.5 cm

Now,

We know,

• TSA of cone = πr(r + l)

Hence,

TSA of cone = 22/7 × 0.7(0.7 + 2.5)

= TSA = 22 × 0.1 × 3.2

= TSA = 7.04

∴ TSA of the cone is 7.04 cm²

Now,

TSA of the remaining solid is as follows:-

TSA of cylinder - TSA of cone

= 13.64 - 7.04

= 6.6 cm²

∴ CSA of the remaining solid is 6.6 cm²

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