The victims have no way to start, and those who will calculate the answer in seconds!Grade 3 Mathematics: Geometry Intuitively Finding Areas, Partitioning Method!Question 360 of Bei Xiao's question set, very difficult!
As shown in Figure 1,
Dig out two small squares with an area of 8 and 2 respectively in the large square, and find the area of the large square and the area of the remaining shaded part.
Super-Curriculum Knowledge Points:The ratio of the area of the square is equal to the square of the ratio of the length of the sides!
Purpose of the Examination:Through graphic segmentation, a preliminary concrete cognition of the above-mentioned super-outline knowledge points is formedIn practice, understand rather than master: the multiple of the area of a square is equal to the product of the multiple of the length of the sides.
Analysis: Segmentation method!
From 8 2 = 4, the square with a cognitive area of 8 can be divided into 4 small squares with an area of 2, as shown in Figure 2.
Observation from Figure 2: 3 small squares with an area of 2 can be placed in the vertical direction of the large square, and thus 3 small squares with an area of 2 can also be placed in the horizontal direction, so a total of 3 3 = 9 small squares with an area of 2 can be placed.
The area of the large square is 9 2 = 18, and the area of the shaded part is 18-8-2 = 8.
From the analysis and , cognition, and induction: the area multiple is equal to the side length multiple multiplied by the side length multiple.
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