| 摘要 |
A ratio La/Lb between lengths La and Lb is defined as a first ratio, and a ratio Sa/Sb between areas Sa and Sb is defined as a second ratio. The first and second ratios are positioned within a region surrounded by lines connecting five points P1 to P5 in a coordinate system in which the first and second ratios are taken as the respective coordinate axes thereof. The point P1 has a first ratio of 0.273 and a second ratio of 0.099. The point P2 has a first ratio of 0.636 and a second ratio of 0.099. The point P3 has a first ratio of 0.836 and a second ratio of 0.496. The point P4 has a first ratio of 0.545 and a second ratio of 0.496. The point P5 has a first ratio of 0.236 and a second ratio of 0.215. |
