Embedded Files
Relating the area of a rectangle to the area of a parallelogram
Relating the area of a rectangle to the area of a parallelogram
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On an iPad? Select the 3 dots in the top right hand corner, Share and Export then Make a Copy.
Content
Content
Expectations: E 2.5 (Grade 5)
Expectations: E 2.5 (Grade 5)
Key Concepts
-When students understand the properties of a rectangle and how to calculate the area, they can apply this to learn the area of a parallelogram.
Learning Goal
Learning Goal
We want students to understand...
We want students to understand...
When you know the properties of rectangles, parallelograms you can figure out the area formulae of both shapes
Success Critera
Success Critera
I can calculate the area of a rectangle.
I can use what I know about the properties of parallelograms, while knowing how to calculate the area of a rectangle to find the area of parallelograms
Pedagogy
Pedagogy
Minds On
Minds On
What shapes can you build with two identical short straws and two identical long straws?
What shapes can you build with two identical short straws and two identical long straws?
(Virtually students can work on the Geoboard app to create their shapes)
Teacher notes: Students can be given two short and two long straws. Some of them will consider only polygons, whereas others may allow for other sorts of shapes as well.
Some students will investigate what they can do only with the given straw lengths. For example, given two 10 cm and two 12 cm straws, they could make a parallelogram of specific dimensions. However, other students might generalize to what happens with any two pairs of side lengths. Some students will assume that four straws must be used and others will consider the possibility of using only three of the straws or maybe even only two of them (to create angles). Every student in the class will be able to attack the problem at some level.
Action!
Action!
Teacher Lead: Cut a parallelogram out of cm grid paper and demonstrate how to transform a parallelogram into a rectangle with the same base length and height by cutting a triangle from one side of the parallelogram and moving it to the opposite end or by cutting to create two trapezoids that can be similarly rearranged.
Teacher Lead: Cut a parallelogram out of cm grid paper and demonstrate how to transform a parallelogram into a rectangle with the same base length and height by cutting a triangle from one side of the parallelogram and moving it to the opposite end or by cutting to create two trapezoids that can be similarly rearranged.
Have students construct and cut out some other parallelograms and test them to see if they can transform them into a rectangle and test them to see if they can be transformed back into a parallelogram.
Have students construct and cut out some other parallelograms and test them to see if they can transform them into a rectangle and test them to see if they can be transformed back into a parallelogram.
Key Understandings:
Key Understandings:
-The Base that is cut remains the same length because the part removed from one end is added to the other end.
-The Base that is cut remains the same length because the part removed from one end is added to the other end.
-The height is measured at right angles to the base.
-The height is measured at right angles to the base.
-A single cut along the height forms both sides of the rectangle
-A single cut along the height forms both sides of the rectangle
consolidation ideas
consolidation ideas
- Using the Geoboard App make a rectangle that is 4 unit height by 5 units base. Calculate the area. (Record on the student handout).
- Now change the rectangle to a parallelogram (same base). What is the area? (Record on the student handout).
- Change the height several times to form a series of other parallelograms, fill in the handout.
Computer: Click File and Make a Copy iPad: Select 3 dots, Share & Export, Make a Copy
- Teacher Note: Some students will be interested to note that either side length of the parallelogram can be used as the base and that they can measure the height from either inside or outside the boundaries of a parallelogram. As long as they measure the height from the side they are using as the base length, the formula will produce the correct area.
Independent Task/Assessment Opportunities
Independent Task/Assessment Opportunities
Using what students have learned about the properties of rectangles and parallelograms. Explore the “which one doesn’t belong” website.
Using what students have learned about the properties of rectangles and parallelograms. Explore the “which one doesn’t belong” website.
Have students create their own “which one doesn’t belong” page, using their knowledge of rectangles and parallelograms
Have students create their own “which one doesn’t belong” page, using their knowledge of rectangles and parallelograms
Independent Task
Independent Task
Additional Follow Up Tasks
Additional Follow Up Tasks
Technology
Technology
virtual manipulative
virtual manipulative
Geoboard App
Geoboard App
in DSB1 App Catalogue
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