Curved Surface Area Solution4

In this page curved surface area solution4 we are going to see solution of some practice questions.

Question 8

The external surface area of a hollow cylinder is 540 Π cm².Its internal diameter is 16 cm and height is 15 cm. Find the total surface area.

Solution:

External surface area of cylinder = 540 Π cm²

                                 2 Π R h = 540 Π cm²

Internal radius (r) = 16/2 = 8 cm

       height (h) = 15 cm

  2 x Π x R x h = 540 Π 

  2 x Π x R x 15 = 540 Π

                     = 540 Π x (1/2) x (1/Π) x (1/15)

                    = 270/(15)

                 R= 18

Total surface area =  2 Π (R + r) (R - r + h)

                                 =  2 Π (18 + 8) (18 - 8 + 15)

                                 =  2 Π (26) (25)

                                 =  1300 Π cm²

Total surface area of the cylinder = 1300 Π cm²

Question 9

The external diameter of the cylindrical shaped iron pipe is 25 cm and its length is 20 cm. If the thickness of the pipe is 1 cm, find the total surface area of the pipe.

Solution:

External radius of the pipe (R) = 12.5 cm

height of the pipe (h) = 20 cm

thickness of the pipe (w) = 1 cm

To find total surface area of the cylinder we have to find the internal radius (r)

      W = R - r

       1 = 12.5 - r

       r = 12.5 - 1

      r = 11 .5 cm

Total surface area = 2 Π (R + r) (R - r + h)

                          = 2 Π (12.5 + 11.5) (12.5 - 11.5 + 20)

                          = 2 (22/7) (24) (21)

                          = 2 (22) (24) (3)

                          = 3168 cm²

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• Area
• Curved Surface Area
• Total Surface Area
• Volume
• Cylinder
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• Sphere
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• Problems on Total Surface Area
• Problems on Volume
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• Perimeter of Sector
• Perimeter of Sector Worksheets
• Length of Arc
• Practice questions on length of arc
• Perimeter of square
• Perimeter of Parallelogram
• Perimeter of Rectangle
• Perimeter of a Triangle
• Area of a Circle
• Area of Semicircle
• Area of Quadrant
• Area of a Sector
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• Area of Equilateral Triangle
• Area of Scalene Triangle
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