| 摘要 |
FIELD: device for illustration of the right angle projection theorem. SUBSTANCE: device for illustration of the right angle projection theorem has two movably joined projecting planes 1 and 3, plane of right angle 6 confined by straight lines a and b and installed movably on axle-clamp 5 for its turning round its one end installed in hole 4 located in the fixed projecting plane 3 near the axle 2 joining planes 1 and 3. Plane 3 is secured to clamp 7. EFFECT: higher evidence of the theorem proof. 1 cl, 2 dwg |
