| 摘要 |
PURPOSE: A ruler is provided to enable a user to easily draw a line without errors by fitting two points to be connected in a groove of the ruler and drawing the line to connect the two points using a pen or a mechanical pencil. CONSTITUTION: A ruler is a plastic ruler surrounding a first groove, a second groove, and a third groove. The ruler includes a scale which is marked in front of the first groove, the second groove, and the third groove. The first groove, the second groove, and the third groove have a tip thickness of a pencil, a ballpoint pen, and a felt-tip pen. The whole ruler is composed of a transparent plastic to enable a user to effectively draw a line between two points.
|
