Properties of 2D ShapesTake a look at some of the language used to describe the properties

of 2-dimensional (2D) shapes below:

curved longer

v

sides

straight shorter 2-dimensional equal

corner symmetry length

Properties of 2D ShapesTake a look at some of the language used to describe the properties

of 2-dimensional (2D) shapes below:

obtuse angle right angle acute angle

circle

1 curved side

0 vertices

almost infinite lines of symmetry

Sum of interior angle is 360°

How many curved sides?

How many vertices?

How many lines of symmetry?

What do all the interior angles

measure?

triangle

3 straight sides

3 vertices

up to 3 lines of symmetry

3 interior angles

How many straight sides?

How many vertices?

How many lines of symmetry?

How many interior angles?

3 acute anglesWhat type of angles can you see in this

shape?

Challenge: What is the sum of all interior angles in a triangle?

180°

square4 straight sides

4 equal length sides

4 vertices

4 lines of symmetry

4 interior angles

4 right angles

How many straight sides?

How many vertices?

How many lines of symmetry?

How many interior angles?

What type of angles can you see in this

shape?

What does each interior angle

measure?

each interior angle is 90°

90° 90°

90° 90°

Challenge: What is the sum of all interior angles in a quadrilateral?

360°

trapezium

4 straight sides2 equal length sides

4 vertices

1 line of symmetry

4 interior angles

2 acute angles2 obtuse angles

How many straight sides?

How many vertices?

How many lines of symmetry?

How many interior angles?

What type of angles can you see in this

shape?

rectangle4 straight sides

2 long sides2 short sides

4 vertices

2 lines of symmetry

4 interior angles

4 right angles

How many straight sides?

How many vertices?

How many lines of symmetry?

How many interior angles?

What type of angles can you see in this

shape?

What does each interior angle

measure?

each interior angle is 90°

90° 90°

90° 90°

rhombus

4 straight sides4 equal length sides

4 vertices

2 lines of symmetry

4 interior angles

2 acute angles2 obtuse angles

How many straight sides?

How many vertices?

How many lines of symmetry?

How many interior angles?

What type of angles can you see in this

shape?

How many pairs of interior angles?

2 pairs of interior angles

regular pentagon

5 straight sides

5 vertices

up to 5 lines of symmetry

5 interior angles

5 obtuse angles

How many straight sides?

How many vertices?

How many lines of symmetry?

How many interior angles?

What type of angles can you see in this

shape?

regular hexagon

6 straight sides

6 vertices

up to 6 lines of symmetry

6 interior angles

How many straight sides?

How many vertices?

How many lines of symmetry?

How many interior angles?

What type of angles can you see in this

shape?6 obtuse angles

regular heptagon

7 straight sides

7 vertices

up to 7 lines of symmetry

7 interior angles

How many straight sides?

How many vertices?

How many lines of symmetry?

How many interior angles?

What type of angles can you see in this

shape?7 obtuse angles

regular octagon

8 straight sides

8 vertices

up to 8 lines of symmetry

8 interior angles

How many straight sides?

How many vertices?

How many lines of symmetry?

How many interior angles?

What type of angles can you see in this

shape?8 obtuse angles

regular nonagon

9 straight sides

9 vertices

up to 9 lines of symmetry

9 interior angles

How many straight sides?

How many vertices?

How many lines of symmetry?

How many interior angles?

What type of angles can you see in this

shape?9 obtuse angles

regular decagon

10 straight sides

10 vertices

up to 10 lines of symmetry

10 interior angles

How many straight sides?

How many vertices?

How many lines of symmetry?

How many interior angles?

What type of angles can you see in this

shape?10 obtuse angles