Question

222 IX-Class MATHEMATICS
Do THESE
Find the Total surface area of each of the following cylinders.
7 cm
7 cm.
250 cm
10 cm
3.3 Volume of a cylinder​

Answer 1

Step-by-step explanation:

1.Given,Radius of cylinder = 7 cm

Height of cylinder = 10 cm

We know that,\bold {Total\ Surface\ Area\ of\ cylinder\ = 2\pi r(r+h)}Total Surface Area of cylinder =2πr(r+h)

=2\times \frac{22}{7}\times 7\times (7+10)}

= 2\times \frac{22}{7}\times 7\times (17)}

= \bold {748\ cm^2}748 cm

2

\bold {Hence,Total\ Surface\Area\ of\ cylinder\ = 748\ cm^2}Hence,Total Surface\Area of cylinder =748 cm

2

2.Given,Height of Cylinder = 7 cm

Area of base = 250\ cm^2250 cm

2

We know that,

Area\ of\ base = \pi r^2Area of base=πr

2

250 = 3.14\times r^2250=3.14×r

2

r = 8.92 cm

So,\bold {Total\ surface\ Area\ of\ cylinder\ = 2\pi r(r+h)}Total surface Area of cylinder =2πr(r+h)

= 2\times \frac{22}{7}\times 8.92\times (8.92+ 7)2×

7

22

×8.92×(8.92+7)

= \bold {892.61\ cm^2}892.61 cm

2

\bold {Hence,Total\ Surface\Area\ of\ cylinder\ = 892.61\ cm^2}Hence,Total Surface\Area of cylinder =892.61 cm

2