What is a square?
A square is a flat shape with four equal straight sides and four right angles.
The answer
A square has 4 sides, 4 vertices, 2 pairs of parallel sides and 4 lines of symmetry. The angles inside a square add up to 360°.
Square diagram and properties
| Property | Count |
|---|---|
| Sides | 4 |
| Vertices (corners) | 4 |
| Angles add up to | 360° |
| Each angle | 90° |
| Right angles | 4 |
| Pairs of parallel sides | 2 |
| Lines of symmetry | 4 |
Key facts about the square
- It is the regular quadrilateral: every side is the same length and every angle is 90°.
- Its 4 lines of symmetry are the 2 diagonals and the 2 lines across the middle.
- A square is a special rectangle, a special rhombus and a special parallelogram, all at once.
- Area = side × side, which is where square numbers get their name.
Where you see it
A chessboard square, a sticky note, a window pane and many floor tiles.
The common mistake
Thinking a square turned on its corner becomes a diamond or a rhombus that is no longer a square. Turning a shape never changes it: it still has four equal sides and four right angles.
An 11+ style question
A square has an area of 49 cm². What is its perimeter?
Answer: 28 cm
- The area is side × side, and 7 × 7 = 49, so each side is 7 cm.
- The perimeter is 4 sides of 7 cm: 4 × 7 = 28 cm.
Related shapes and skills
More shapes
Questions parents ask
How many sides and vertices does a square have?
A square has 4 straight sides and 4 vertices (corners). Its angles add up to 360°.
How many lines of symmetry does a square have?
A square has 4 lines of symmetry.
Is a square a rectangle?
Yes. A rectangle is a four-sided shape with four right angles, and a square has those. A square is the special rectangle whose sides are all equal.
Is a square a regular polygon?
Yes. All four sides are equal and all four angles are equal (90°), so a square is the regular quadrilateral.
Shape questions are quick marks in the 11+
Angles, symmetry, nets and 3D shapes come up in 11+ maths and non-verbal reasoning. The free diagnostic checks maths, English and both kinds of reasoning, and shows what to practise next. No card is required.