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Area of Triangles

Introduction

We know how to find the areas of squares and rectangles. We then used this to find the areas of parallelograms. Can we use the area of a parallelogram to find the area of a triangle?

What is the area of the parallelogram?

Select all that apply
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  • D

How do you know this is the area of the parallelogram?

Move the triangles to see which ones will fit into the parallelogram. Which ones fit?

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  • E

You could use the area of the parallelogram to find the area of some of these triangles. Which ones?

Select all that apply
  • A
  • B
  • C
  • D
  • E

Why did you choose these triangles?

Are there any common features between the triangles you chose? Are there any differences?

What are the areas of the triangles you chose? How do you know this is the correct area? (Relate this back to the parallelogram).