7.4 Special Quadrilaterals

• Wiskunde
• Middelbare school
• vwo
• Leerjaar 1

Good morning!

Schedule: 

• 7.4 Learning goals
• Special Quadrilaterals
• Work on your homework

Learning goals 

At the end of these two lessons I can:

• Recognize when a quadrilateral is a parallelogram, rhombus, trapezium and/or kite. 
• Name the properties of a parallelogram, rhombus, trapezium and/or kite. 
• Use the correct symbols to note when two sides are perpendicular, parallel and/or equal

What is a quadrilateral?

How many axes of symmetry does this star have?

1. 4
2. 5
3. 6
4. 0

Theory A: Parallelogram

Properties of a parallelogram:

• A parallelogram has rotational symmetry of order 2 or through 180 degrees.
• Because of that  the opposite angles are equal (ask yourself why)
• The diagonals divide each other exactly in half
• Th

Theory A: Parallelogram

More properties of a parallelogram:

• Opposite sides have the same length
• The diagonals divide each other exactly in half
• The diagonals are not perpendicular

Theory B: Rhombus

Properties of a rhombus:

• The diagonals are the axes of symmetry
• The diagonals are perpendicular
• All properties of a parallelogram also hold for a rhombus, therefore a rhombus is a special parallelogram

Theory C: Kite

Properties of a kite:

• One OR more diagonal axis of symmetry. The diagonals are perpendicular
• the adjacent (aangrenzende) sides are equal
• angle A = angle C

Parallelogram

Rhombus

Kite

Checklist

Are both pairs of sides of the quadrilateral parallel? 

Are all the sides of the quadrilateral equal? 

Is at least one pair of sides of the quadrilateral parallel? 

Is at least one diagonal of the quadrilateral an axis of symmetry?

Parallelogram

Rhombus

Kite

Trapezium

Take out your diaries 

Homework for Thursday 3-6-2021:

Vwo and Havo/Vwo                  p. 62 #37-51

What would you like to do? 

I want to work on the exercises #37-51 (p. 62) on my own. 

or 

I want to work out an exercise with ma'am on the bord

Learning goals 

At the end of these two lessons I can:

• Recognize when a quadrilateral is a parallelogram, rhombus, trapezium and/or kite. 
• Name the properties of a parallelogram, rhombus, trapezium and/or kite. 
• Use the correct symbols to note when two sides are perpendicular, parallel and/or equal