Question

please give these answers​

Answer 1

Answer:

writing samaj ne aari please write neatly

Answer 2

Step-by-step explanation:

(Total 5 questions)

Questions and solutions :-

1) If r = 7cm,h = 28;CSA of cylinder = ?

Sol)

Formula :-

• CSA of a cylinder = 2πrh

Substitute the values in the formula :

• CSA = 2π x 7 x 28
• CSA = 2 x 22/7 x 7 x 28
• CSA = 2 x 22 x 28
• CSA = 1232cm²

2) If l = 20cm,b = 10cm,h = 15cm ; volume of the cuboid = ?

Sol)

Formula :-

• volume of a cuboid,v = l x b x h

Substitute the values in the formula :-

• v = 20 x 10 x 15
• v = 3000cm³

(Note :- A cube has all the sides equal. But the given values are not same as each. So,the given values are of a cuboid.)

3) If r = 14cm,h = 4.2cm ; TSA of the cylinder = ?

Sol)

Formula :-

• TSA of a cylinder = 2πr(r+h)

Substitute the values in the formula :-

• TSA = 2 x 22/7 x 14(14 + 4.2)
• TSA = 2 x 22 x 7(14 + 4.2)
• TSA = 2 x 22 x 7(18.2)
• TSA = 5605.6cm²

4) If r = 14cm,h = 2.1cm ; volume of cylinder = ?

Sol)

Formula :-

• Volume of a cylinder,v = πr²h

Substitute the values in the formula :-

• v = 22/7 x 14 X 14 x 2.1
• v = 22 x 2 x 14 x 2.1
• v = 1293.6cm³

5) If r = 7cm ; area of base of the cylinder = ?

Sol)

Formula :-

The base of the cylinder is a circle. So area of a circle has to be calculated.

• a = πr²

Substitute the values in the formula :-

• a = 22/7 x 7 x 7
• a = 22 x 7
• a = 154cm²

Hope it helps