Skip to main content

Maths · Geometry

Identify a shape property

Identify one stated property of a 2D or 3D shape.

Free to use and free to share. There is no sign-up, no score, and nothing a child does here is recorded or sent anywhere.

Practise it now

Exactly one of these readings comes out different. Which one?

This exercise practises identify a shape property alongside its own main skill, What Stays the Same When a Shape Moves.

Loading the interactive exercise. Nothing you do here is saved or scored.

A worked example

One question of the kind this skill is tested with, worked all the way through: the reasoning, and what the wrong answers are there to catch.

Reading a property off a shape

How many right angles does this shape have?

Work through the right angles of this pentagon.

  1. 2
  2. 4
  3. 3
  4. 5

Answer: 3

How you get there

3 of this pentagon's corners open to exactly 90°, a quarter turn, so it has 3 right angles. Its other corners are wider or narrower than that.

Why the other answers tempt

The number of sides is not the number of right angles - a shape can have four sides and no right angle at all.

If they are stuck, say this

Check each corner against the square corner of a page - only the ones that match exactly are right angles.

Now do it live in Spot the Changed Reading

What this exercise is doing

Spot the Changed Reading

Exactly one of these readings comes out different. Which one?

This engine’s own main skill is What Stays the Same When a Shape Moves. It practises identify a shape property alongside it.

The programme is “Slide 4 right”, then “Slide 2 right”, then “Flip in the line x = 4”. Every move on that list picks the outline up and puts it down without changing its size or shape, so the lengths of the sides, the angles at the corners and the area inside are all exactly what they were. What a rigid motion does change is WHERE things are, and here that is the coordinates of corner A. There is one more thing a flip changes and a slide or a turn never does: the letters ran anticlockwise round the outline and now run clockwise. The exam-safe habit is to sort every reading into "about the shape itself" or "about where the shape is": the first kind always survives, the second kind is the only place an answer can hide.

  1. Step 1. Watch it move. Play the cards and watch the readings.
  2. Step 2. The odd one out. Which single reading came out different?

What to say if they get stuck

  1. Tap a reading and it is drawn twice: once on the faint outline where the shape started, once on the solid one where it is now. Scrub slowly and watch whether the two marks stay the same.
  2. A slide, a turn and a flip all pick the outline up without stretching or squashing it, so every length, every angle and the area come through untouched.
  3. A flip is the only one of the three that reverses the outline, and this programme has one of them, so the letters end up reading round the other way.

Open Spot the Changed Reading on its own page to share it

How identify a shape property differs from the skills beside it

The same exercise practises several skills, and telling them apart is often the difficulty rather than the exercise itself. On this page the skill is: identify one stated property of a 2d or 3d shape, and it stops where excludes calculating measure.

  • Preserve measure under a rigid transformation

    Use the fact that translation, rotation, and reflection preserve lengths and angles. Excludes calculating an unknown measure from unrelated angle or length rules.

  • Reflect a shape

    Identify the result of one reflection in a stated mirror line. Excludes rotation and translation.

  • Rotate a shape

    Identify the result of one stated rotation. Centre, direction, and turn are fixed.

Related maths skills

All maths 11+ skills

Questions parents ask about identify a shape property

Answered from what the skill map records about this skill, not from a template. Every answer here is on the page, and the same questions are the page's FAQ structured data.

Identify one stated property of a 2D or 3D shape. It is one of 55 named maths skills in the 11+, in the geometry strand, and this page carries 1 interactive exercise that practises it.

Knowing which maths topic to practise is most of the work

A free diagnostic covers arithmetic, fractions, geometry, measure and data handling, and comes back with the topics to spend the next few weeks on.