12 E + 12 F Area of a triangle and parallelogram

• Wiskunde
• WO
• Studiejaar 2

Area of Triangle and Parallelogram

Schedule: 

• Learning goals 
• Revision 
• Area of a triangle
• Area of a parallelogram 

Learning goals 

At the end of this lesson I can:

•  Calculate the area of rectangles
• Calculate the are of triangles 
• Calculate the area of parallelogram 

Area of a rectangle

What is the formula for the area of a rectangle ?

What kinds of units do we use for area? 

Area of a rectangle

Area of a rectangle = Length · Width 

You express area in squares... cm²  m²  ft²

What is the formula for the area of a triangle?

Area of a triangle

Area of a triangle =

The Base is often the bottom of the shape

The Height is Perpendicular to the Base

​2​​1​​⋅base⋅height

What is a parallelogram?

Area of a parallelogram 

Area of a parallelogram = 

How can you find the height in a parallelogram? 

Base⋅Height

Area of a parallelogram 

Area of a parallelogram = 

How can you find the height in a parallelogram? 

Which other area formula is this very similar to? 

Base⋅Height

Area of a parallelogram 

Area of a parallelogram = 

 

Area of a rectangle = 

Base⋅Height

length⋅width

Practice

Find the area's of the following polygons

A

B

C

Practice

Find the area's of the following polygons

A = 20m2

B = 10

C = 2 + 6 = 8

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                                                               

Extra practice + help

p. 259 : 12E             1abcgh, 3

P. 260: 12F               1abcf, 2               

Extra practice

p. 259 : 12E             1defgh, 2, 3

P. 260: 12F               1def, 2, 3, 4              

Challenge

p. 259 : 12E             1ghi, 2, 4

P. 260: 12F               1def, 2, 3, 4              

           ManageBac > Files > Unit 5 Measurements > Surface area 1

          ManageBac > Files > Unit 5 Measurements > Surface area 2

          ManageBac > Files > Unit 5 Measurements > Area and surface area composite figures (don't do the last question)

Homework

P. 257        12D: 7 

P. 260       12E: 2

P. 261        12F: 4

Area and perimeter in the classroom

Go and find different objects in the classroom to measure. 

Calculate the area and perimeter of at least 3 different objects and record this information in your notebook. 

Don't forget your units!!!!