Grades 8-12
Mathematics
Geometry
Standard 10

Students compute areas of polygons including
rectangles, scalene triangles, equilateral
triangles, rhombi, parallelograms,
and trapezoids.


 
Resources
Lesson Plans
Assessments
Geometry 
Larson/Boswell/Stiff, 1995,
D.C. Heath and Company
 

Section References

6.1 Exploring Polygons

6.2 Angles of Polygons

6.3 Properties of Parallelograms

6.4 Proving Quadrilaterals 
are Parallelograms

6.5 Special Parallelograms

6.6 Trapezoids

6.7 Extended Applications: Congruence and Kites

11.1 Exploring Area and Perimeter

11.2 Areas of Parallelograms and Triangles

11.3 Areas of Other Quadrilaterals

11.4 Areas of Regular Polygons

Software

Geometer's Sketchpad 3,
Key Curriculum Press 1995
floppy mac/windows

Specific Textbook 
Web Sites

http://www.glencoe.com/
sec/math/prealg/mathnet/

http://www.eduplace.com/
links/

http://www.eduplace.com/

http://www.hmco.com/
college/mathematics/
index.html

http://www.mcdougallittell
.com/

http://www.hmco.com/

http://www.SRA-4KIDS.com/

General Math 
Reference Sites

http://www.learner.org/
sami/view-category.php3
?category=math

http://www.score.k12.ca.us/

http://henson.austin.apple
.com/edres/curric.shtml

http://school.discovery.com/
schrockguide/index.html

http://www.EDsOasis.org/

http://www.math.com/

http://www.nea.org/grants/
free.html

http://www.wcom.com/
marcopolo/

http://www.udel.edu/sine/

http://dewey.chs.chico.k12
.ca.us/math.html

Free Stuff

http://www.nea.org/
grants/free.html

State/National Math 
Ed Organizations

http://www.nctm.org/

http://www.cde.ca.gov/

Calif. Dept. of Ed. Standards, Assessment, Ed. Reference.

Calculator Reference Site

http://www.ti.com/
calc/docs/calchome.html

Previously Published Data

1.) Working with graph paper, students will count the squares inside a rectangle to find its area. As they find the area of different rectangles, they will keep track, using a table, of the length, width, and area of each. Students will see a pattern and a connection between length, width, and area. 

2.) Working with scissors, students will cut out a parallelogram. Then they will cut perpendicular to the long side and turn the parallelogram into a rectangle. They then can find the area of the rectangle which will show them the area of the parallelogram. Students will find the relationship between the rectangle and the original parallelogram and derive the formula for the area of a parallelogram. 
3.) Working with scissors, students will cut out two identical triangles. Then they will cut along the altitude of one of the triangles and reassemble the triangle into a rectangle. This will show them the area of a triangle is half the area of a parallelogram. Students will find the relationship between the rectangle and the triangles and derive the area of a triangle. 
4.) Working with scissors, students will cut out a trapezoid and a rhombus. Then they will cut the shapes so they can form triangles, which will lead them to the areas of the original objects. Students will find the relationship between the two triangles and the trapezoid and derive the formula for the area of a trapezoid.
Previously Published Data

1.) Given or shown any of the shapes, students will write the formula for the area. In addition, students are able to calculate the area for that particular shape. 

2.) Using the process of finding triangles in different shapes, students will find the areas of other shapes.