2D Shapes Vocabulary

Let’s see how many words we use to describe or are

connected with 2D shapes

2D shapes - words

In pairs, talk about the words and decide on a definition to share with the group

Tessellation – is covering an area with shapes leaving no spaces

You can use the same shape.

Tessellation – is covering an area with shapes leaving no spaces

You can use the same shape.

Return

Symmetry is when both sides of the shape or pattern are the same when viewed from

the central line. Some shapes have a line (or lines) of symmetry -

sometimes called 'mirror lines'.

In each case, if you stood a mirror on the line of symmetry, the shape would look unchanged. (You can check this by using a mirror, or by tracing a shape and folding it along the mirror line.)

<<< <<<

<<< <<<

Patterns can also be symmetrical

**** +++ ****

****************

**** +++ ****

Draw the line(s) of symmetry on the shapes above

What is a

polygon?

A shape

with many

sides and

angles.

Regular polygons are a never-ending series of shapes with one special feature

All the sides and angles are the same size.

Do you know any regular polygons?.

Here are some a regular polygons?

Equilateral Triangle

3 sides

3 equal angles

4 sides

4 equal angles

6 sides

6 equal angles

8 sides

8 equal angles

Square

Hexagon Octagon

Click anywhere on the page until you fill all the boxes

What are the properties of these regular polygons?

Pentagon

Heptagon

Decagon

Nonagon

Write your answers and check them by clicking 4 times

A pentagon has 5 equal sides and 5 equal angles

A heptagon has 7 equal sides and 7 equal angles

A decagon has 10 equal sides and 10 equal angles

A nonagon has 9 equal sides and 9 equal angles

• A circle is a flat round shape.

• The distance from the centre to the outside of the circle is always equal.

Circle Vocabulary

A circle has one side around the

outside called the circumference

Diameter is any line across the circle that passes through the centre of the circle

Radius is any line that is drawn between the centre of the circle to the circumference

Parallel Lines

Two lines are parallel if they are always the same distance apart. This means they will never meet even if they are extended

<

<

<The arrowhead indicate that these two lines are

parallel

Parallel Lines

Some shapes have 1 or 2 pairs of parallel lines

<The arrowhead indicate that these two lines are

Sometimes << arrowheads are used to show a second pair of

parallel lines

<

<

<

<<

<

<<

<<

<<<<

2D ( 2 dimensional)Here is a line. This has one dimension (length) 

All flat shapes have two dimensions,

length and width (breadth). So they are called 2D.

What is an angle?When two lines join two angles are formed.

When two lines intersect 4 angles are formed

XX

X

X

X

X

Angles are measured with a protractor

6001200

Two angles are formed. One angle is 1200 and the other is 600.

Together they make 1800.

Angles are measured with a protractor

A right-angle is 90o

Angles are measured with a protractor

Two right-angles are 180o Four right-angles are 360o

A circle has 360o around its centre point

Two right-angles are 180o Four right-angles are 360o

What is a complex shape?A complex shape is a shape that can be broken into smaller shapes. What shapes can you see in these complex shapes?

Recap

3. Name 6 regular polygons. List their properties

1. What is a polygon?

2. What is a regular polygon?

Next

Recap Answers1. A polygon is a many sided shape

2. A regular polygon is a shape with equal sides and equal angles

3 Any of the following:• Equilateral Triangle – 3 equal sides & angles Square – 4 equal sides 4 right-angles Pentagon – 5 equal sides & angles Hexagon – 6 equal sides & angles Heptagon – 7 equal sides & angles Octagon – 8 equal sides & angles Nonagon – 9 equal sides & angles Decagon – 10 equal sides & angles

2D shapes – words – student record 1

2D shapes – words – student record 2

What shapes can you see in this picture?

What shapes can you see in this picture?

What shapes can you see in this picture?