Page 1 - Lesson Notes-2-Ch.13 SA and Volumes(Cylinder)
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SAI International School
                                                     CLASS - IX

               Mathematics
               CHAPTER-13: SURFACE AREAS AND VOLUMES

               LESSON NOTE-2 [CYLINDER]
                CYLINDER


               A cylinder is a solid which has a uniform, circular cross-section.

               If we fold a rectangular sheet with one side as its axis then it forms a cylinder. It is
               the curved surface of the cylinder. And if this curved surface is covered by two
               parallel circular bases then it forms a right circular cylinder.
























               RIGHT CIRCULAR CYLINDER


               If the base radius is perpendicular to the height, then the cylinder is called a Right
               Circular Cylinder. Generally, we will discuss only on Right circular cylinder. Now we
               will assume cylinder as Right Circular Cylinder.

                Right Circular Cylinder
                Let the radius of base of cylinder be ‘r’ and height be ‘h’.

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                   1.  Area of base of Right Circular cylinder =       sq. unit
                   2.  Circumference (Perimeter) of base = 2    
                    3.   Curved Surface Area (CSA)/Lateral Surface Area= 2    ℎ sq. unit
                    4.   Total Surface Area (TSA) =Area of 2 circular bases+ CSA
                                                           = 2     2    + 2    ℎ
                                                      = 2    (   + ℎ)  sq. unit
                    5. Volume of Right Circular Cylinder =Area of base × Height

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