# Area of Triangles

# Area of Triangles

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

Discovering the Area Formula for TrianglesArea 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.

Answer the following questions in your math journal:

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

Documents for download:

# Area of Parallelograms

# Area of Parallelograms

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

Finding the area of ParallelogramsUse 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 CutterUse the Area Tool for Parallelograms to verify conjectures:

Area ToolNOTES: 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.

Answer the following questions in your math journal:

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

Documents for download:

# Area of Trapezoids

# Area of Trapezoids

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

Finding the area of TrapezoidsUse 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 CutterNOTE: 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 ToolNOTE: 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.

Answer the following questions in your math journal:

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

Documents for download: