---
title: "Defining attributes of shapes"
description: "Distinguish defining attributes of shapes (e.g. triangles are closed and three-sided) from non-defining attributes (e.g. colour, orientation, overall size)"
canonical: https://lightmysky.com/learn/mathematics/defining-attributes-of-shapes-mt_bfhng6mOuy
source: https://lightmysky.com/learn/mathematics/defining-attributes-of-shapes-mt_bfhng6mOuy.md
retrieved: 2026-09-02
---

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# Defining attributes of shapes

Distinguish defining attributes of shapes (e.g. triangles are closed and three-sided) from non-defining attributes (e.g. colour, orientation, overall size)

Subject: Mathematics · Area: Geometry · Ages 6 to 7
Page: https://lightmysky.com/learn/mathematics/defining-attributes-of-shapes-mt_bfhng6mOuy

## Ready when they can

- Build and draw shapes that possess defining attributes
- Identify that a shape remains a triangle regardless of its size, colour, or orientation
- Explain why a given shape is or is not a particular type based on its defining properties

## Lesson: What makes a triangle a triangle

Every triangle has 3 straight sides and 3 corners. That is what makes it a triangle. It does not matter what color it is, how big it is, or which way it is turned.

*(drawing: Turn this triangle, shrink it, or paint it purple. It still has 3 straight sides and 3 corners. Still a triangle.)*

**Example.** Mia draws a tiny green triangle on her paper. Then she draws a huge yellow triangle next to it. They look very different, but both have 3 straight sides that join up with no gaps, and 3 corners. So both are triangles.

To check if a shape is a triangle, do not look at the color or the size. Count the straight sides. If there are 3 sides and 3 corners, and the sides join up with no gaps, it is a triangle.

**Recap.** A triangle is a triangle because of its 3 sides and 3 corners, never because of its color, size, or direction.

## Practice

14 questions on this page, each with its working shown.

## Needs first

- [2-D shapes](https://lightmysky.com/learn/mathematics/2-d-shapes-mt_KJeEeTutJI)
- [3-D shapes (age 5+)](https://lightmysky.com/learn/mathematics/3-d-shapes-age-5-mt_yGv8doDAmp)

## Opens up

- [2-D shapes (age 6+)](https://lightmysky.com/learn/mathematics/2-d-shapes-age-6-mt_sBcRdUfAzV)
- [Drawing shapes with given attributes](https://lightmysky.com/learn/mathematics/drawing-shapes-with-given-attributes-mt_zuOGOGFAKb)