Page 106 - trackpad v5.1 class 4 flipbook
P. 106

Look at these polygons that can be made using the repeat block.



                              Polygon                                   Command




                   Triangle                          Repeat 3 [Move 100 Steps → Turn 120 degrees]

                   Square                            Repeat 4 [Move 100 Steps → Turn 90 degrees]

                   Pentagon                          Repeat 5 [Move 100 Steps → Turn 72 degrees]


                   Hexagon                           Repeat 6 [Move 100 Steps → Turn 60 degrees]


                   Heptagon                          Repeat 7 [Move 100 Steps → Turn 51 degrees]

                   Octagon                           Repeat 8 [Move 100 Steps → Turn 45 degrees]

                   Nonagon                           Repeat 9 [Move 100 Steps → Turn 40 degrees]


                   Decagon                           Repeat 10 [Move 100 Steps → Turn 36 degrees]

                  To draw polygons in Scratch, you must remember three points:

                  1.   You must know the number of sides in the shape. This is the value to be given in repeat
                     block.
                  2.  Each time a repeat command is used, you draw a line and turn at a corner.

                  3.  You must know the degree of the angle at the corner. It is very easy to calculate this.

                     Just divide 360 by the number of sides in the shape.


                  Drawing a Square With and Without Using Repeat Block
                  Create the given Script and observe the sprite moving and turning only four times to draw

                  a square using repeat block. Click four times on the  when         clicked  block to draw a square
                  without using repeat block.

                        when  clicked                                 when  clicked
                            pen down                                      pen down
                        repeat  4                                         set pen color to
                          move 100   steps                                set to pen size 5
                          turn   90  degrees                          move 50   steps
                                                                      turn    90  degrees



                  Drawing A Circle

                  To draw a circle, create the given script in Scratch.




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