Introduction Completion of Figures - General Intelligence and Reasoning for SSC CGL

Introduction

Completion of figures is a common non-verbal reasoning topic in competitive examinations. In these questions a part of a figure is missing and the candidate must choose the option that, when placed in the missing area, completes the figure so that the whole pattern remains consistent.

• Rotational symmetry through an angle of 90°
• Diagonally opposite parts are similar
• Adjacent parts are laterally/vertically inverted images
• Based on a certain repeating design or pattern

Each question consists of two components: the question figure (incomplete) and the answer figures (options). The missing portion is usually shown by a question mark (?). The task is to identify which answer figure correctly fills the missing part so that the completed figure follows the same design rules as the given parts.

Tips on cracking Completion of Figures

Time management is crucial in competitive exams. Figure-completion questions test visual reasoning and pattern recognition under time constraints. Use the following general approaches to increase speed and accuracy:

• Quickly try simple geometric transformations such as rotation, reflection (lateral or vertical), or translation.
• Look for symmetry (rotational or mirror), repeating motifs, and the relative orientation of small elements.
• Compare the missing quadrant/part with other parts of the figure to deduce the transformation required.
• Eliminate options that clearly conflict with the basic rules observed in the rest of the figure.

Types of Completion Questions and Worked Examples

Type 1: Rotational Symmetry Through an Angle of 90°

Tip: In these questions, the figure repeats itself every 90°. Each quadrant (or equal part) is the same design rotated by 90° clockwise or anticlockwise. To find the missing part, rotate any known part by 90° in the required direction.

Example1: Identify the missing part of the given figure and select it from given answer figures.

Ans: (b)

All three visible equal parts have the same design, each rotated 90° clockwise relative to the previous one. Rotate the known part by 90° clockwise to obtain the missing portion; option (b) matches this rotated design.

Example2: Identify the missing part of the given figure and select it from given answer figures.

Ans: (c)

The three shown parts are identical under a 90° clockwise rotation. Rotating the adjacent part by 90° clockwise produces option (c). Compare the rotated subfigure with the option figures to confirm.

Example3: Which of the answer figures given will complete the pattern of the question figure?

Ans: (b)

Each equal part repeats after a 90° clockwise rotation. Rotate the known part through 90° clockwise to obtain the missing portion and verify that option (b) matches.

Example 4: In the following question, complete the missing portion of the question figure by selecting from the given answer figures (a), (b), (c) and (d).

Ans: (c)

All visible parts are related by a 90° clockwise rotation. Rotate the indicated part by 90° clockwise and compare; option (c) is the correct rotated piece and completes the figure.

Option (c) replaces (?) to make the overall design consistent with 90° rotational symmetry.

Type 2: Diagonally Opposite Parts are Similar

Tip: In these questions the diagonally opposite parts share the same design. The whole figure often has 180° rotational symmetry: rotating the entire figure by 180° produces the same appearance. If one part is missing, it can often be obtained by a 180° rotation of the diagonally opposite part.

In the figure, parts 1 and 3 are identical and parts 2 and 4 are identical. A 180° rotation transforms the figure into itself.

Example 1: Identify the missing part of the question figure and select it from given answer figures.

Ans: (c)

Since diagonally opposite parts are identical, rotate the diagonally opposite part by 180° to obtain the missing section. Option (c) matches the rotated design and completes the figure.

Example2: Identify the missing part of the question figure and select it from given answer figures.

Ans: (a)

The diagonally opposite sections are identical. A 180° rotation of the corresponding visible part yields the missing piece; option (a) fits correctly.

Type 3: Adjacent Parts are Laterally / Vertically Inverted Images

Tip: Adjacent parts may be mirror-images of one another, either by lateral (left-right) inversion or vertical (top-bottom) inversion. Use mirror-reflection to generate the missing section from an adjacent part.

In the figure, parts 1 and 2 are laterally inverted images; parts 3 and 4 are laterally inverted images; 1 and 4, 2 and 3 are vertically inverted pairs. If one part is missing, obtain it by reflecting the appropriate adjacent part.

Example1: Identify the missing part of the question figure and select it from given answer figures

Ans: (a)

The top two adjacent parts are lateral inverses of each other and the left two are vertical inverses. The missing part (4) must be the lateral inversion of part (3). Option (a) is the lateral inversion of (3) and completes the pattern.

Example2: Identify the missing part of the question figure and select it from given answer figures

Ans: (d)

Observe lateral inversion between adjacent parts. The missing piece should be the lateral inversion of the adjacent known part (3). Option (d) matches this lateral inversion and replaces (?) to complete the figure.

Type 4: Based on a Certain Design or Pattern

Tip: These questions do not follow simple rotation or mirror rules. Instead, a repeated motif, progressive change, or alternating-line pattern governs the design. Identify the rule that controls the repetition or progression and choose the option that follows it.

This type tests careful observation of small details: repeated strokes, alternation, incremental changes in orientation, or the way elements are paired.

Example1: Identify the missing part of the question figure and select it from the answer figures.

Ans: (b)

On analysis, the pattern shows a doubled-lined triangle motif repeating in a specific way. Option (b) matches the required motif and completes the figure.

Example2: Identify the missing part of the question figure and select it from the answer figures.

Ans: (d)

The design elements repeat in alternate lines. Option (d) follows the same repetition rule and correctly completes the pattern.

How to approach these questions in an exam

• First, scan the whole figure to detect obvious symmetry, rotation, or reflection patterns.
• If nothing obvious appears, compare the missing part with each visible part one by one to see if a simple transformation (90° rotation, 180° rotation, lateral mirror, vertical mirror) maps one to the other.
• Use elimination: discard choices that introduce elements not present anywhere in the question figure.
• If the pattern appears progressive (changes across parts), identify the rule of progression before choosing the option.
• Practice a variety of patterns to build speed and familiarity with common transformations.

Summary

Completion of figures requires careful observation of symmetry, rotation and reflection, and an understanding of repeated design rules. Practise recognising which transformation (90° rotation, 180° rotation, lateral/vertical inversion or a repeating motif) applies, and then apply it to the appropriate known part to find the missing piece quickly and accurately.