| 摘要 |
A drawing board and drawing instrument combination is provided. The drawing board (10) has grooves (14) along three of its edges and at 45 DEG across the corners which can receive tongues (18) provided on either side of a flat drawing instrument (12). The instrument (12) has a number of straight edges (20, 22, 24, 26, 28) which overlie the board in use and which make different angles to the edge of the board. The instrument (12) serves as a T-square and also as a set-square, and is reversible. |
