| 摘要 |
<p>A protractor for simplifying the plotting of indifference curves has a triangular shape, with two equal sides and with the right angled corner opposite the hypotenuse cut out into an approximate hyperbola symmetric about a middle line (8). The radius of the curve decreases a little towards the edges. The protractor is marked with parallel lines (5, 6), parallel to the two catheters, to enable the user to draw different scaled curves. The two sets of guide lines intersect on the middle line to the hypotenuse. The protractor can be made of transparent plastic and the markings can be printed and/or embossed.</p> |
