Area of Triangles

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

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:

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?

Documents for download:

• Area Forms: Squares and Rectangles
• Area Forms: Unknown Triangles
• Area Forms: Bermuda Triangle

Area of Parallelograms

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

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:

Use the Area Tool for Parallelograms to verify conjectures:

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.

Answer the following questions in your math journal:

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?

Documents for download:

• Area Forms: Rectangles and Parallelograms
• Area Forms: Quadrilateral Area Record

Area of Trapezoids

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

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:

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:

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.

Answer the following questions in your math journal:

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

Documents for download:

• Area Forms: Trapezoids
• Area Forms: Centimeter Grid Paper

Summary of Area

Click the below link to view a summary of area.