Year level: 7

Strand: Space

Lesson length: 60 mins

As geometric explorers, students use intuition and logic to establish the side and angle properties of triangles and special quadrilaterals.

### Achievement standard

Students classify polygons according to their features

### Content descriptions

Students classify triangles, and other polygons according to their side and properties; identify and reason about relationships. AC9M7SP02

### General capabilities

Numeracy

• understanding geometric properties (Level 4)

Critical and Creative Thinking

• draw conclusions and provide reasons (Level 5)

### Cross-curriculum priority

Asia and Australia’s engagement in Asia

This lesson presents opportunities for assessment as described below.

Show the 321 Exit slip (slide 15) or read it out.

• 3 geometric properties I learned today.
• 1 question I still have.

Set the following tasks and students can finish it for homework to hand in later.

• Geometric Patterns remaining activities in the properties of quadrilaterals worksheet handed earlier.
• Students create a concept map showing all the connections between the special quadrilaterals.
• Acute, obtuse and right angle
• Bisect, intersect, diagonal
• Axis of symmetry

An area of challenge for students is recognising the properties of plane shapes when they have a different orientation. For example, a square that is displayed diagonally or an irregular five-sided shape is a pentagon.

## What you need:

• Lesson plan (Word)

• Teacher's slides (PowerPoint)

• Design from Asia worksheet (Word)

• Classifying triangles template (Word, print A3)

• Impossible triangles poster activity (Word, print A3)

• Properties of quadrilaterals worksheet (Word)

• Blu tac, A3/poster paper, coloured markers, ruler, pencil, eraser, scissors