What is the perimeter of a rectangle (a combination of a rectangle and a square)? )
After combining a rectangle and a square, calculate the combined perimeter, or calculate the perimeter of one of the shapes by knowing the perimeter of the combined shape, or calculate the side length of a certain shape, and so on.
The main thing here is to examine children’s observation ability and thinking ability.
The knowledge points investigated include translation, equivalent replacement, ***.
Today we will sort out these difficulties and divide them into the following situations:
1. The situation of equal width or equal length
Equal side width means The length of a side of a square is equal to the width of a rectangle.
The length of an equal side is the length of a side of a square and the length of a rectangle.
We have done three questions, each of which is a situation.
In this case, the sides of the square are equal to the width of the rectangle. Can draw for children.
Although there are many variations in each situation, and many situations may arise in the calculation process, the basic calculation and thinking process is the same.
That is to say, whether it is equal width or equal length, their calculation and thinking methods are the same.
2 . The side length of a square is not equal to the width and length of a rectangle.
In this case, generally speaking, the side length of the square will be between width and length, and the question type will vary greatly. Please refer to the following questions for the calculation process and thinking process.
The seventh question is a graph provided by the parents, which is a combination of two rectangles, but its calculation process and thinking direction are the same as the sixth question. The sixth question can have many kinds of friends and friend resources, but the calculation results are the same.
So, as long as children master these basic calculation skills and ideas, no matter how the graphics are placed or changed, they can easily calculate them.
3. Graphic cutting method,
This kind of graphics is also very common in the exam, but if you master the skills, the calculation is just as simple. But when doing this kind of questions, it is recommended that parents take a piece of paper and cut it out for their children to read. It will be easier to understand by looking at an example. But whether it is a square or a rectangle, its calculation method is the same.
Summary: There are many combinations of rectangles and squares, but the way of calculation, after thinking about it, is basically here. If the child still can’t master it, you can watch related videos under Youyou, which will help you understand.