Area and Perimeter of Regular Polygons

Square

Content Objective:

Students will rediscover the method of finding the perimeter and area of squares.

Materials:

Rulers for pairs, square perimeter worksheet, square area worksheet

Procedure:

Perimeter

1. Collectively recall the definition of perimeter given on review day. Have students get into pairs and distribute perimeter worksheet. Once worksheet is complete and students have compared their answers, ask the class as a whole the following questions:

What do you notice about the side lengths of our squares?

What happens to the perimeter when the side lengths are changed?

Is there a way to find the perimeter of a square without measuring all four sides? What if you were only given the length of the diagonal, how would you find the side lengths?

2. Demonstrate using Geometer's Sketchpad the properties of the side lengths of squares. Click here to use the GSP file.


Area

1. Collectively recall the definition of area given on review day. Now, have students get back into pairs and distribute area worksheet. Once worksheet is complete and students have compared their answers, ask the class as a whole the following questions:

Again, what do you notice about the side lengths of our squares?

What happens to the area when the side lengths are changed?

How is the length of one side related to the area of the square?

Is there a way to find the area of a square with one side length? What about with only the length of the diagonal?

2. Demonstrate using Geometer's Sketchpad the properties of the base and altitude of regular triangles. Click here to use the GSP file.


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