RULER FOR READING AND WRITING ANGLE

摘要

PURPOSE: To accurately draw linear segments making a certain angle with respect to a standard line by rendering the linear segment connecting two points of 0 and 180 degrees form a single side of ruler. CONSTITUTION: A standard line 5 is drawn on a draft 4. After making the standard line 5 agree with protracting line 2 on the ruler 1 to which corresponding angular degrees have been indicated, a straight line is drawn along the side A of the ruler 1. This line becomes the desired segment 8. Because the linear segment connecting points of 0 and 180 degrees of angle indication digit 3 agrees with the side A of the ruler 1, desired linear segments can simply be drawn at a time and mistake in marking can be eliminated. Next, the ruler 1 is made parallel translation S to another standard line 7 by means of auxiliary ruler 6. When the protracting line 2 superposes on the standard line 7, lines are drawn along the side A.