Back ] Up ] Next ] [Timeline]

Grade 8:  The Learning Equation Math

31.01 Polygons and Circles

 Measurement Refresher pp 50-51
Learning Outcomes:

The student will:

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.

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

Trapezium

Trapezoid
Parallelogram
Kite
Rectangle
Rhombus
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

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

• Continue until you have all of the answers correct.
• Click if you want to repeat the activity.

Number Correct:

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

4

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

Angles and Parallel Lines:  Grade 7 Lesson 32.02

Back ] Up ] Next ] [Timeline]