A symmetry line is a line that divides an object into two identical parts.
When a figure is folded in half along its symmetry line, the two parts perfectly match.
The axis of symmetry is the name given to this line of symmetry.
There is no line of symmetry in a scalene triangle, parallelogram, or trapezium, because no line separates these geometries into two identical shapes.
Final Answer:
Hence, three examples of shapes with no line of symmetry are (i) Quadrilateral (ii) Scalene triangle and (iii) Parallelogram.