NCERT Exemplar Solutions
Class 6 - Mathematics - Unit 9: Symmetry and Practical Geometry - Fill in the BlanksQuestion 34
Class 6 - Mathematics - Unit 9: Symmetry and Practical Geometry - Fill in the Blanks
Question. 34
The number of capital letters of the English alphabets having no line of symmetry is ____.
Answer:
10 (F, G, J, L, N, P, Q, R, S, Z).
Detailed Answer with Explanation:
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What is a line of symmetry?
A line of symmetry divides a shape into two exact mirror halves.
If you fold the shape along this line, both parts match perfectly.
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How to test a letter for symmetry
Use the “fold test” in your mind:
- Vertical fold: Imagine folding the letter from top to bottom through the middle.
- Horizontal fold: Imagine folding the letter from left to right through the middle.
If neither fold makes two identical halves, the letter has no line of symmetry.
Note: We use standard block (print) capital letters, like the ones on classroom charts.
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Examples (just to understand)
Some letters like A or O can be split into matching halves (they have symmetry).
Now we will look for letters that do not split into matching halves.
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Letters with no line of symmetry
- F – The top and middle bars make the two sides different.
- G – The open gap and inner stroke break the balance.
- J – The bottom curve and the top differ across any fold.
- L – One long vertical and one short horizontal line do not match.
- N – The diagonal slant means the halves don’t mirror.
- P – The loop on one side has no matching part on the other side.
- Q – The tail breaks the mirror match.
- R – The leg and loop make the two sides different.
- S – The top and bottom curves are not mirror halves.
- Z – The slant makes top and bottom positions different.
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Count them
There are 10 such letters: F, G, J, L, N, P, Q, R, S, Z.