In this way, every two sticks form four right angles, one * * is three combinations (1, 2, 1, 3, 2, 3) and one *** 12 right angle.
Extended data
This problem needs to use spatial imagination.
Spatial imagination is people's abstract thinking ability to observe, analyze and understand the spatial form (spatial geometry) of objective things.
It mainly includes the following three aspects:
(1) can display the corresponding spatial geometry in the brain according to the spatial geometry or according to the language and symbols expressing the geometry, and can correctly imagine its intuition.
(2) According to the stereogram, we can display the geometric shape represented by the stereogram and the shape, positional relationship and quantitative relationship of its components in the brain.
(3) Be able to decompose and combine the existing spatial geometric shapes in your mind, generate new spatial geometric shapes, and correctly analyze their positional and quantitative relationships.
Cultivating students' spatial imagination is one of the main tasks and difficulties in middle school mathematics teaching.
In teaching, if the term "spatial imagination" is mentioned too much, and the rational analysis is not enough to grasp the training law, it may lead to the result that a few savvy students' spatial imagination has been improved, but most students have benefited little, and even regard the study of "solid geometry" as a timid road.
Baidu encyclopedia-space imagination