Geometry – Properties of Shape
MYP Year 2 Mathematics – Geometry: Properties of Shape
This whole topic is really one skill repeated six ways: look at a shape, name a property, then prove you're right using a rule — not a guess, not 'it looks like it'. Examiners give marks for the justification (the angle sum, the tick marks, the Pythagorean check), never for the label alone. Every real exam question below hides a small trap: a classmate's wrong claim, a measurement assumption, or a definition you have to apply exactly as written.
Overview
Properties of Shape is the study of what makes a figure that figure — its side relationships, its angles, its symmetry, and how it compares to other figures. Six ideas run through every question: classify by measurement, prove using a rule, and check your classification survives real-world imperfection (bent wood, sloped land, rounding).
- Triangles and polygons are classified two independent ways — by sides AND by angles. A triangle can be both scalene and obtuse at once.
- Symmetry and tessellation are about a shape mapping onto itself — through a mirror line (reflection) or a turn (rotation).
- Congruence means identical; similarity means same shape, different size, connected by a single scale factor.
- Circles bring their own vocabulary — mixing up 'radius' and 'diameter' in a formula is the single most common circle error.
- Angle rules (triangle sum, parallel-line angles, exterior angle) are the proof engine behind almost every classification claim in this topic.
The shape of the chapter
Command terms this topic tests constantly
| Command term | What it demands | AO | Mark-earning move |
|---|---|---|---|
| Identify | Pick out and name a feature from given information | Knowing & Understanding | 1 mark for the correct name only — no working needed. |
| State | Give a fact or rule with no explanation | Knowing & Understanding | 1 mark for the correct statement — extra detail earns nothing more. |
| Calculate | Obtain a numerical answer, showing the method used | Applying & Reasoning | Working must be visible — an unsupported final answer that's wrong scores 0, even if close. |
| Describe | Give a detailed, specific account of a relationship or process | Communicating | Vague answers ('they are related') score 0 — name the actual rule. |
| Explain | Give reasons for why something happens, not just what happens | Applying & Reasoning | Restating the fact without the 'why' behind it scores 0. |
| Compare | Give similarities AND differences between two things | Applying & Reasoning | Discussing only one item loses roughly half the marks. |
| Justify | Support a conclusion with valid evidence or calculation | Applying & Reasoning | A correct conclusion with no supporting working scores 0 for the justification mark. |
Key point
Overview