| 摘要 |
PROBLEM TO BE SOLVED: To solve problems in a conventional triangle in which triangles are used in two sets and stacked in two pieces in the storage, and accordingly they becomes bulky, also, the minimum angle capable of being drawn by the triangles is 15 degree, so that the angle less than that cannot be drawn, and to provide the present invention eliminating the above drawbacks.SOLUTION: A triangle set is assumed by forming one set of a normal isosceles right triangle and a right triangle. The hollowing capable of measuring an angle of 10 degree is provided in a conventional isosceles right triangle ruler constituted at angles of 45 degree, 45 degree and 90 degree, and the isosceles right triangle ruler with the hollowing is formed. The hollowing corresponding to a visible outline of the isosceles right triangle ruler with the hollowing is provided in a conventional right triangle ruler constituted at the angles of 30 degree, 60 degree and 90 degree, and the right triangle ruler with the hollowing is formed. The triangle set capable of drawing of 5-degree unit characterized by the above is provided.SELECTED DRAWING: Figure 1 |
