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Symmetrical Completion

Symmetrical Completion problems present a figure that is partially complete, with one side missing elements that mirror the other side. You must identify which elements need to be added to make the figure bilaterally symmetric (mirror image across a vertical or horizontal axis). Common examples include butterfly wings, leaf patterns, and floral designs.

10Worksheets
200+Practice Questions
BeginnerDifficulty
1-2 hoursHours to Master

What You'll Learn

Introduction & Overview Why This Matters How to Solve Pro Tips & Tricks
Shortcut Methods Common Mistakes Practice Worksheets Exam Importance

Introduction to Symmetrical Completion

Symmetrical Completion problems present a figure that is partially complete, with one side missing elements that mirror the other side. You must identify which elements need to be added to make the figure bilaterally symmetric (mirror image across a vertical or horizontal axis). Common examples include butterfly wings, leaf patterns, and floral designs.

Prerequisites

Understanding of bilateral (mirror) symmetry Concept of left-right reflection Basic shape recognition Visual pattern matching
Why This Matters: Symmetrical Completion problems appear in 1-2 questions in SSC CGL and Banking PO exams. They test understanding of bilateral symmetry and mirror image concepts.

How to Solve Symmetrical Completion Problems

1

Step 1: Identify the axis of symmetry (vertical, horizontal, or diagonal)

2

Step 2: Observe the pattern on the complete side of the axis

3

Step 3: The missing side must be the mirror image of the complete side

4

Step 4: For vertical symmetry, left mirrors right; for horizontal symmetry, top mirrors bottom

5

Step 5: Count the number of elements needed to mirror the complete side

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Step 6: The elements to add are the mirror images of the elements on the complete side

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Step 7: Verify that the completed figure is perfectly symmetric

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Step 8: Select the correct answer option

Pro Strategy: Always identify the axis of symmetry first. For bilateral symmetry, the missing side must be an exact mirror image of the existing side. The distance of each element from the axis must be preserved in the mirror image.

Example Problem

Example: A butterfly has a left wing with 3 dots. The right wing is missing dots. How many dots should be added to the right wing for symmetry? Solution: Step 1: Axis of symmetry = vertical (left-right mirror) Step 2: Left wing has 3 dots Step 3: Right wing must mirror left wing Step 4: Right wing needs 3 dots in mirror positions Answer: 3 dots

Pro Tips & Tricks

  • Vertical symmetry: left side mirrors right side
  • Horizontal symmetry: top mirrors bottom
  • Diagonal symmetry: mirror across a 45° line
  • The number of elements on both sides must be equal
  • The distance from the axis is preserved in the mirror image
  • Elements may be mirrored (e.g., left-pointing arrow becomes right-pointing)

Shortcut Methods to Solve Faster

For vertical symmetry, left = mirror of right
For horizontal symmetry, top = mirror of bottom
The missing side's pattern is the reverse order of the existing side
If one side has n elements, the other side needs n elements

Common Mistakes to Avoid

Copying the pattern instead of mirroring it
Forgetting that elements themselves may be mirrored (e.g., arrows flip direction)
Not preserving distance from the axis
Assuming all symmetrical patterns have vertical symmetry

Exam Importance

Symmetrical Completion is an important topic for various competitive exams. Here's how frequently it appears:

SSC CGL
1-2 questions
BANKING PO
1-2 questions
RAILWAYS RRB
1-2 questions
INSURANCE
1-2 questions

Ready to Master Symmetrical Completion?

Start with Worksheet 1 and work your way up to expert level! Each worksheet includes:

20 practice questions
Detailed solutions
Step-by-step explanations
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