Abstract
From Meiji era, space geometry and the descriptive geometry had been taught separately in mathematics and drawing, respectively. Under the 1942/43 syllabi, descriptive geometry was widely adopted in mathematics course and used as a problem solving tool. But in the post-war secondary school, the projection skills have been treated just as one of the ways of expression of space figures. Here I considered an instructional plan of space figures utilizing skills of the descriptive geometry. It starts with a sketch of a cube, and finishes with a projection chart of two orthogonal cylinders. It also contains the developed drawing which is important to re-construct the original solid. I also showed a way of investigation on cross sections of a cube using projection, connected with its sketch. I would like to make this consideration more precise with other instructional materials including PC software and develop a curriculum on space geometry of secondary schools.
