| 摘要 |
A visual display device comprises a block of equilateral triangular cross-section. The block has two sides of trapezoidal configuration, a third side of rectangular configuration, a base of equilateral triangular configuration and a top of isosceles triangular configuration. The base is perpendicular to the three sides. The top triangle is at an angle of inclination with the base and has an angle at the corner joining the two opaque sides of trapezoidal configuration and an opaque opposite side coincident with the top edge of the third side and farther from the base than the angle. A light is provided at the base of the block.
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