Shapes

• Wiskunde
• Middelbare school
• vwo
• Leerjaar 1

Shapes

The shapes on the first slide have a name. 

Do you know them?

triangle

circle

square

rectangle

How could you tell these shapes apart?

Properties

The numbers of angles, the length of the sides (compared to each other), the size of the angles.......

These are called the properties of a shape.

The colour and how big they are, are NOT properties in maths. 

Let us do a quizz

You will get a description and you write what shape it is.

What am I?
I have 4 sides, I have 4 angles, I have two shortes sides and two longer sides.

What am I?
All my sides are equally as long (= even lang), I have three angles and three sides.

What am I?
I have 1 curved side.
I have no angles

What am I?
I have 4 angles and 4 sides.
All sides have the same length.

What am I?

I have 4 angles and 4 sides.

All sides have the same length.

We answered a square to the question above.

But does the description also go with the shapes on the right?

More properties and names

rhombus

parallelogram

diagonals

kite

arrowhead

trapezium

Isosceles

equilateral

scalene

regular

irregular

quadrilateral

polygons

pentagon

parallel

perpendicular

angle

right

hexagon

octagon

Triangles

Isosceles: two sides the same

Equilateral: all sides the same

Right- angle: with an angle of 90 degrees

Scalene: nothing special

What kind of triangle is this?

1. Scalene
2. Right-angle
3. Isosceles
4. Equilateral

What kind of triangle is this?

1. Scalene
2. Right-angle
3. Isosceles
4. Equilateral

What kind of triangle is this?

1. Scalene
2. Right-angle
3. Isosceles
4. Equilateral

What kind of triangle is this?

1. Scalene
2. Right-angle
3. Isosceles
4. Equilateral

What kind of triangle is this?

1. Scalene
2. Right-angle
3. Isosceles
4. Equilateral

What kind of triangle is this?

1. Scalene
2. Right-angle
3. Isosceles
4. Equilateral

quadrilaterals

names

1. square

2. rhombus

3. rectangle

4. trapezium (UK)  trapazoid (US)

5. parallellogram

6. arrowhead

1.

2.

3.

4.

5.

6.

Look at the picture. How many quadrilaterals do you see?

How many quadrilaterals did you see?

Look at the picture. How many squares do you see?

how many squares did you see

Look at the picture. How many trapeziums do you see?

how many trapeziums do you see?

quadrilaterals properties diagonals

• Diagonals are lines inside the figure. 
• They can be perpendicular to each other. 
• Cut each other in half (bisect) 
• They can be equally as long or of different sizes.

quadrilaterals properties sides and angles

• Sides can be equal or equal in pairs. 
• They can be perpendicular to each other (90 degrees) or parallel (train rails)
• Angles can be right (90 degrees)
• Opposite angles can be the same or different.
• The angle can be cut each in half (bisect) by the diagonal
• 
  

Fill in the correct word.

The opposite sides of a trapezium are .......

1. the same length
2. perpendicular (90 degrees)
3. parallel (train rails)
4. diagonal

Think about a rectangle and drag the right word to the right place.

One of the targets is used twice.

Opposite sides are

All angles are

The diagonals are

The diagonals ....... each other

right

bisect

parallel

equal

Fill in the correct words
In a kite the diagonals are ....(1)... and
one pair of opposite ....(2)... are the same

1. 1=parallel 2=sides
2. 1= parallel 2= angles
3. 1= perpendicular 2=sides
4. 1= perpendicular 2= angles