Shape-Based Patterns

Shape-based patterns are among the most common and most intuitive rules in AR questions. They focus on the type of shape present in each box — whether a box contains circles, triangles, squares, pentagons, or other geometric figures. Mastering these patterns is your first step towards building a comprehensive pattern library.

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Why Shape Type Matters

Test designers frequently use shape type as a rule because it is visually obvious once you know to look for it, but easy to overlook when you are distracted by other features like colour or size. The key is to always check shape type as part of your systematic scan.

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The Common Shapes in UCAT AR

Before examining rules, ensure you can instantly recognise these shapes:

Shape	Sides	Key feature
Circle	0 (curved)	No straight edges, perfectly round
Semi-circle	0 (curved)	Half a circle, one curved edge, one straight diameter
Triangle	3	Includes equilateral, isosceles, right-angled, and scalene
Square	4	All sides equal, all angles 90°
Rectangle	4	Opposite sides equal, all angles 90°
Diamond (rhombus)	4	All sides equal, rotated square appearance
Parallelogram	4	Opposite sides parallel, slanted rectangle
Trapezium	4	One pair of parallel sides
Pentagon	5	Regular pentagons are common; irregular ones appear occasionally
Hexagon	6	Regular hexagons are most common
Arrow	Varies	Pointed shape indicating direction; can be 5-sided or 7-sided
Star	Varies	Usually 5-pointed (10 sides) or 6-pointed (12 sides)
Cross/plus	12	Plus-sign shape
Heart	Curved	Sometimes appears as a distractor

Important: In the UCAT, circles are classified as curved shapes (0 straight sides). This distinction between straight-sided and curved shapes is the basis of many rules.

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Category 1: Presence or Absence of a Specific Shape

The simplest shape-based rule is: "Every box in Set A contains [specific shape]; Set B does not."

Worked Example

Set A:

• Box 1: Two circles, one triangle, one square
• Box 2: One circle, three pentagons
• Box 3: Four circles, two rectangles
• Box 4: One circle, one hexagon, one arrow
• Box 5: Three circles
• Box 6: One circle, two diamonds, one star

Set B:

• Box 1: Two triangles, one square, one pentagon
• Box 2: One hexagon, two rectangles
• Box 3: Three arrows, one star
• Box 4: Four squares
• Box 5: One triangle, one pentagon, one diamond
• Box 6: Two hexagons, one rectangle, one arrow

Rule: Every box in Set A contains at least one circle. No box in Set B contains a circle.

Why this is easy to miss: If you are focused on counting shapes or checking colours, you might not notice that the defining feature is simply the presence or absence of one particular shape type.

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Category 2: Straight-Sided vs Curved Shapes

This is one of the most frequently tested distinctions in UCAT AR.

The Straight-Curved Classification

Straight-sided	Curved
Triangles	Circles
Squares, rectangles	Semi-circles
Pentagons, hexagons	Ovals/ellipses
Diamonds, parallelograms	Hearts
Arrows (straight edges)	Curved arrows
Stars	Crescents
Crosses

Worked Example

Set A: Every box contains only shapes with straight edges — triangles, squares, pentagons, hexagons, arrows, stars. No circles or curved shapes appear anywhere in Set A.

Set B: Every box contains at least one curved shape — a circle, semi-circle, or oval — alongside any number of straight-sided shapes.

Test shape: A box containing two squares and an oval.

• Contains a curved shape (the oval) → matches Set B's pattern.
• Answer: Set B

Test shape: A box containing a pentagon, a triangle, and a hexagon.

• All shapes have straight edges → matches Set A.
• Answer: Set A

Test shape: A box containing only a single circle.

• Contains a curved shape → could be Set B.
• But Set B boxes typically contain a mix. Does Set B's rule require straight shapes too? Go back and check. If Set B's rule is simply "contains at least one curved shape", then this fits Set B.
• Answer: Set B

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Category 3: Number of Sides

Rules based on the number of sides are extremely common and often form part of compound rules.

Common Side-Count Rules

• Total sides per box is constant: "The total number of sides of all shapes in each box equals 12"
• Total sides is odd/even: "In Set A, the total number of sides is always even"
• All shapes have the same number of sides: "Every shape in each box has exactly 4 sides"
• Range of sides: "Every box contains shapes with 3, 4, and 5 sides (one of each)"

Worked Example: Total Sides Equals a Constant