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SAI International School


                                            Class :  VI


        Mathematics


        Chapter - 4 – Basic Geometrical Ideas


        Lesson Note – 4.2


        Subtopics:

                    Curves
                     simple curves

                     closed curves
                     open curves

                    Non-Simple curve
                    polygon


        Concepts       Definition                                     Example

        Curves               A curve is a continuous and
                              smooth flowing line without any
                              sharp turns.
                             One way to recognize a curve is
                              that it bends and changes its
                              direction at least once.
                             A curve can be straight also.






        simple               A simple curve changes direction
        curves                but does not cross itself while
                              changing direction.
                             A simple curve can be open and
                              closed both.



        closed               A closed curve has no end points
        curves                and encloses an area (or a region).
                             It is formed by joining the end
                              points of an open curve together.
                             Examples: Ellipse , Circle.

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