Revised Mathematics TEKS

Area of Triangles

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.

 

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 of Parallelograms

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.

 

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 of Trapezoids

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.

 

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:

 

Summary of Area

Summary of Area


Click the below link to view a summary of area.

Summary of Area