1. Understanding of graphics

Through observation and operation activities, we can intuitively understand the common plane graphics such as rectangle, square, triangle, parallelogram and circle, know the names of these graphics, and identify and distinguish them.

Process and Method Objectives: In the inquiry activities such as comparison, touching and painting, the plane figure is abstracted from the surface of the object, the relationship between "face" and "body" is intuitively perceived, the relationship between "shape" and "body" is understood, the preliminary observation, operation, comparison and imagination abilities are cultivated, the preliminary space concept is established, and the preliminary geometric intuition and image thinking are developed.

2. Measurement of graphics

The focus of graphic measurement is to determine the size of the graphic.

Teachers should let students experience the process of unifying measurement units, feel the significance of unifying measurement units, and understand the length, angle, perimeter, area and volume of graphs based on measurement units. In order to make students realize that the understanding of graphics is closely related to measurement, in the process of deducing some commonly used calculation methods of graphics perimeter, area and volume, they should feel the mathematical measurement method and gradually form a sense of quantity and reasoning.

3. The movement of graphics

1. Translation: Translation does not change the shape and size of the graph. Three elements of translation: the position of the original characters, the direction of translation and the distance of translation. Translation method: translate the points first, and then connect the points in turn.

2. Rotation: rotation direction: rotation can be divided into counterclockwise rotation or clockwise rotation, and the clockwise direction is consistent with the movement direction of the hands on the clock face. Special rotation: the rectangle rotates 180 degrees around the midpoint and coincides with the original. The square rotates 90 degrees around the midpoint and coincides with the original square. The equilateral triangle rotates 120 degrees around the midpoint, which coincides with the original drawing.

3. Axisymmetric: A graph is folded in half along a straight line, and the graphs on both sides of the straight line can completely overlap, then this graph is an axisymmetric graph, and this straight line is called the axis of symmetry.