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If the number of sides of a regular poly...

If the number of sides of a regular polygon is n, then the number of lines of symmetry is equal to

A

2n

B

n

C

`(n)/(2)`

D

`n^(2)`

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The correct Answer is:
To find the number of lines of symmetry in a regular polygon with \( n \) sides, we can follow these steps: ### Step 1: Understand the Concept of Lines of Symmetry A line of symmetry is a line that divides a shape into two identical parts that are mirror images of each other. For regular polygons, the lines of symmetry can be drawn through the vertices and midpoints of the sides. **Hint:** Think about how many ways you can fold the polygon so that both halves match perfectly. ### Step 2: Analyze Different Regular Polygons Let's consider a few examples of regular polygons: - **Triangle (3 sides)**: A triangle has 3 lines of symmetry. Each line can be drawn from a vertex to the midpoint of the opposite side. - **Square (4 sides)**: A square has 4 lines of symmetry. These include two vertical and horizontal lines, as well as two diagonal lines. - **Pentagon (5 sides)**: A regular pentagon has 5 lines of symmetry, with each line going from a vertex to the midpoint of the opposite side. **Hint:** Draw the polygons and try to identify the lines of symmetry visually. ### Step 3: Generalize the Pattern From the examples above, we can see that for any regular polygon with \( n \) sides, there are exactly \( n \) lines of symmetry. This is because: - Each vertex can connect to the midpoint of the opposite side, creating a line of symmetry. - Additionally, lines can be drawn through the midpoints of opposite sides. **Hint:** Consider how the symmetry works for polygons with more sides. Does the pattern hold? ### Step 4: Conclusion Thus, we conclude that for a regular polygon with \( n \) sides, the number of lines of symmetry is equal to \( n \). **Final Answer:** The number of lines of symmetry in a regular polygon with \( n \) sides is \( n \). ---
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BHARDWAJ ACADEMY-GEOMETRY-Chapter Exercise (Pervious Years Questions)
  1. The number of lines of symmetry of the figure is

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  2. In Delta PQT, PQ = PT. The points R and S are on QT such that PR = PS....

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  3. If for Delta ABC and lt DEF the correspondence CAB harr EDF gives a co...

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  4. Find the number of vertices in a polyhedron which has 30 edges and 12 ...

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  5. In Delta PQR, PQ = 4cm, PR = 6 cm and QR =3 cm. Which of the following...

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  6. In Delta ABC and Delta LMN, AB=LM, AC = LN and angle B = angle M. Then...

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  7. A polyhedron has 6 faces and 8 vertices. How many edges does it have?

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  8. The sum of all interior angles of a polygon is 1440^(@). The number of...

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  9. If one of the angles of a triangle is 130^(@) , then the angle between...

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  10. In the adjacent figure, the bisectors of angleA and angleB meet in a p...

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  11. The sum of all interior angles of a regular polygon is 1080^(@). What ...

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  12. In Delta DEF and Delta PQR, if PQ =DE, EF=PR and FD =QR, then

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  13. The interior angle of a regular polygon is 156^0dot Find the number of...

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  14. If the number of sides of a regular polygon is n, then the number of l...

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  15. In which one of the following cases, the construction of a quadrilater...

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  16. Let x be the angle which is equal to its complement and y be the angle...

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  17. How many sides has a regular polygon, each angle of which is of mea...

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  18. The angles of a quadrilateral are in the ratio 2 : 3 : 5 : 8. The sum ...

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  19. If one of the angles of a triangle is 110°, then the angle between the...

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  20. In Delta ABC, AB= 4cm, AC = 5 cm and BC = 6 cm. In Delta PQR, PR = 4 c...

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