12G Area of a trapezium + area of composite figures

• Wiskunde
• Middelbare school
• vwo
• Leerjaar 2

Area of trapeziums and composite figures 

Schedule: 

• Learning goals
• Revision 
• Area of a trapezium 
• Area of composite figures 

Learning goals 

At the end of this lesson I can:

•  Calculate the area of any trapezium 
• Calculate the area of a composite figure 

1. A
2. B
3. C
4. D

1. A
2. B
3. C
4. D

What is a trapezium?

Area of a trapezium

A quadrilateral with at least one pair of parallel lines

Area of a trapezium = 

​2​​(a+b)h​​

Area of a trapezium

Find the area

Done? Can you answer this: 

Find the area

Done? Can you answer this: 

A=​2​​(3+7)⋅4​​=

A=​2​​(14+11)⋅10​​=

A=​2​​(12+20)⋅7​​=

20 cm2

125 cm2

112 cm2

Area rectangle = 70·165 = 11550 m2

Area trapezium =                              21175 m2

Total Area = 11550 + 21175 = 32725 m2

Money earned in total = 7 · 32725 = 229 075 pounds

​2​​(165+220)⋅110​​=

What to do

- I really want a challenge                                                  Open the Pink slides on LessonUP

- I understand it, but I think a                                           Open the Blue slides on LessonUp

 bit more practice will help me                 

- I think more practice will help me,                             Work with the board

and would like to do more board work                                                               

Area of composite figures 

Basic shapes: square, rectangle, triangle, parallelogram, trapezium

Composite shape: A shape created with 2 or more basic shapes. 

Extra practice + help

p. 262 : 12G             1abc, 2, 4

ManageBac > Files > Unit 5: Measurement > Area of compound shapes 1 (questions 2-6)

                                  

Extra practice

p. 262 : 12G             1abc, 3, 4

ManageBac > Files > Unit 5: Measurement > Area of compound shapes 1 (Questions 2-6)

ManageBac > Files > Unit 5: Measurement > 

                                  

Challenge

p. 262 : 12G             3, 4

ManageBac > Files > Unit 5: Measurement > Area of compound shapes 2

ManageBac > Files > Unit 5: Measurement > Surface area 2