# Area of Triangles

Use the Instructional Plan for Lesson 1 as described at the following link:

Discovering the Area Formula for Triangles
Area Tool

NOTES: When using the Area Tool for Triangles,

• be sure to click on the TRIANGLES button before beginning the exploration, and
• click and drag the vertices until AB and CD are whole number values.

1. How does the area of a triangle compare to the area of a rectangle with the same base length and height?
2. Do you think this will work for any triangle? Why or why not?

# Area of Parallelograms

Use the Instructional Plan for Lesson 3 as described at the following link:

Finding the area of Parallelograms

Use the Shape Cutter Tool to illustrate how the area of a parallelogram can be rearranged to form a rectangle with the same base and height:

Shape Cutter

Use the Area Tool for Parallelograms to verify conjectures:

Area Tool

NOTES: When using the Area Tool for Parallelograms,

• be sure to click on the PARALLELOGRAMS button before beginning the exploration, and
• click and drag the vertices until AB and CE are whole number values.

1. How does the area of a parallelogram compare to the area of a rectangle with the same base length and height?
2. Do you think this will work for any parallelogram? Why or why not?

# Area of Trapezoids

Use the Instructional Plan for Lesson 2 as described at the following link:

Finding the area of Trapezoids

Use the Shape Cutter Tool to illustrate how the area of a trapezoid can be rearranged to form a parallelogram with the same base and height:

Shape Cutter

NOTE: Consider drawing a few of the trapezoids from the Trapezoids Recording Sheet to use as examples when illustrating the Shape Cutter Tool.

Use the Area Tool for Trapezoids to verify conjectures:

Area Tool

NOTE: When using the Area Tool for Trapezoids,

• be sure to click on the TRAPEZOIDS button before beginning the exploration, and
• click and drag the vertices until PQ and CE are whole number values.

1. How does the area of a trapezoid compare to the area of a parallelogram with the same base length and height?

# Summary of Area

Click the below link to view a summary of area.

Summary of Area