NCERT Exemplar Solutions
Class 6 - Mathematics - Unit 9: Symmetry and Practical Geometry - Fill in the Blanks

Question 20

What is a line of symmetry?

A line of symmetry is a line that divides a shape into two exact matching halves.

Rectangle (not a square):

• Draw a line through the middle from top to bottom. This is one symmetry line.
• Draw a line through the middle from left to right. This is another symmetry line.
• So, a rectangle has 2 lines of symmetry: (2).
• Note: These lines are through the midpoints and are parallel to the sides, not diagonals.

Rhombus (all sides equal, not necessarily a square):

• The two diagonals of a rhombus cut it into matching halves.
• Each diagonal is a line of symmetry.
• So, a rhombus has 2 lines of symmetry: (2).

Compare:

Rectangle has (2) lines of symmetry. Rhombus has (2) lines of symmetry.

Therefore, the numbers are equal.