Which of the following are models for perpendicular lines: (a) The adjacent edges of a table top. (b) The lines of a railway track. (c) The line segments forming a letter ‘L’. (d) The letter V.

(a) Yes, the adjacent edges of a table top are the models of perpendicular lines. (b) No, the lines of a railway tracks are parallel to each other. So they are not a model for perpendicular lines. (c) Yes, the two line segments of‘L’ are the model for perpendicular lines. (d) No, the two line segments of ‘V’ are not a model for perpendicular lines.