Line test - graphic reasoning -5- one stroke class

Catalog

One 、 Definition

Two 、 How to judge the number of strokes

3、 ... and 、 Example

  Four 、 skill

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One 、 Definition

         One stroke figure ： Can a picture not be repeated , Draw with one stroke without interruption .

Two 、 How to judge the number of strokes

        1. The number of graphics contains “ singularity ” Number .

                 singularity ： If the number of lines starting from one point is odd , Then this point is called “ singularity ”.

        2. When the total odd number of figures is 0 or 2 when , This figure is a stroke figure ; Otherwise, it is a multi stroke figure , And the minimum number of strokes required for the graph = Odd number of points /2.

                The first picture has four singularities （ Three endpoints + An intersection ）; The second picture has four singularities ; The third picture has two singularities （ Two endpoints ）. So the first two pictures can be drawn with at least two strokes , The third picture is a stroke .

                The lines at the intersection of the above two drawings are 4, For the even , So there is no singularity . Odd number is 0, For a stroke of graphics .

3、 ... and 、 Example

1.

 1,2,3 Odd number is 2, For a stroke of graphics ;4,5,6 Odd number is 4, For two strokes .

2.

It can be seen that all images are one stroke graphics , So choose C.

3.

1,2,5 For a stroke of graphics ;3,4,6 For two strokes .

 

  Four 、 skill

        When the figure is a stroke figure at a glance , Consider whether you are examining a stroke ; Or when there are multiple figures in the title 0 A figure consisting of a singularity figure （ Like a circle 、 Five-pointed star ） when , You can also consider whether you are examining a stroke . for example ：