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Grade 8:  The Learning Equation Math

31.01 Polygons and Circles

3icon.gif (4368 bytes)

Measurement

Refresher pp 50-51

Learning Outcomes:

The student will:

Quadrilateral

What is a quadrilateral?
Click and drag the interactive vertices of the quadrilateral below. What remains the same about the sketch? We will study perimeter in more detail in a future lesson.

 

What is a circle?
Click and drage the handle provided in the circle below. What remains the same about the shape? We will study perimeter and area in more detail in a future lesson.

 

 

 

Quadrilaterals

Click on the polgon for interactive version. The first one may be slow loading.

Type of Quadrilateral Diagram

Trapezium

quadrilateral.gif (1280 bytes)

Trapezoid polygon8.gif (1052 bytes)
Parallelogram parallelogram.gif (994 bytes)
Kite polygon10.gif (988 bytes)
Rectangle rectangle.gif (1199 bytes)
Rhombus rhombus.gif (1060 bytes)
Square
modified source: Polygons

 

Regular Polygons

If all sides of a polygon have equal lengths and if all angles have the same measure then the polygon is called a Regular Polygon. Move the slider below to see examples of regular polygons. The perimeter (P) and area (A) calculations will be studied in a future lesson. What remains the same for each regular polygon? We will study perimeter and area in more detail in a future lesson.

Below you will pictures of some common regular polygons. Click on the polgon for interactive version. The first one may be slow loading.

Regular Polygon Name Diagram # Lines of Symmetry

Regular Triangle (Equilateral Triangle)

3

Regular Quadrilateral (Square)

4

Regular Pentagon 5
Regular Hexagon 6
Regular Octagon 8
modified source: Polygons

 

The Angles of a Regular Polygon

Directions:    Give the program the number of sides of a regular polygon and it will give you the name of the polygon(up to 10 sides), the sum of the measure of the interior angles, the measure of each interior angle, and the measure of each exterior angle.


Number of Sides:  
Name of the polygon:  
Sum of the measure of the interior angles:  
Measure of each interior angle:  
Measure of each exterior angle:  

Equation:    Interior: (n-2)*180/2 - Exterior: 360/n

Source:  http://www.javascripts.com  (Dustin Everett)

 

Review:
 

Identify each polygon according to its formal name

  • Click box to check your answers.  Any answers which are incorrect will be cleared.
  • Continue until you have all of the answers correct.
  • Click if you want to repeat the activity.

Number Correct:

 

Check your score!

source:  http://www.coe.tamu.edu/~strader/Mathematics/Geometry/PolygonLesson/identify.html

 

Key Terms:

polygon, regular, congruent, equidistant, triangle, right angle, rectangle, square, quadrilateral, diagonal, bisect, adjacent, parallel, parallelogram, rhombus, trapezoid, isosceles, trapezium, convex, concave, kite, chevron

Prerequisite Skills:

Polygons and Circles:  Grade 8 Lesson 31.01

Regular Polygons

If all sides of a polygon have equal lengths and if all angles have the same measure then the polygon is called a Regular Polygon. Move the slider below to see examples of regular polygons. The perimeter (P) and area (A) calculations will be studied in a future lesson.

Below you will pictures of some common regular polygons. Click on the polgon for interactive version. The first one may be slow loading.

Regular Polygon Name Diagram # Lines of Symmetry

Regular Triangle (Equilateral Triangle)

3

Regular Quadrilateral (Square)

4

Regular Pentagon 5
Regular Hexagon 6
Regular Octagon 8
modified source: Polygons

 Classifying Angles: Grade 7 Lesson 32.01

Angles and Parallel Lines:  Grade 7 Lesson 32.02

Angles and Parallel Lines 2:  Grade 7 Lesson 32.03

Constructing Bisectors:  Grade 7 Lesson 32.05

 

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Comments to:  Jim Reed
Started September, 1998. Copyright 1999, 2000

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