This document is a self-learning kit on geometry for 7th grade students that defines and illustrates convex polygons. It contains objectives, credits to reference books and websites, a review on internal and external regions of a polygon, a discussion defining convex and concave polygons with examples, interactive activities for students, and web links for additional learning.

1. Mathematics Teachers Association of the Philippines
Self Learning Kit : Grade 7 – Geometry
Convex Polygon
Objectives Credits Review Discussion Activities Web Links
Click the icons to navigate.
Prepared by: Mr. Alvin Patrick Q. Peñaflorida
VALENZUELA NATIONAL HIGH SCHOOL
Division of City Schools -
VALENZUELA

2. Objectives
Define and illustrate convex
polygons
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3. Credits
Reference Books:
1. E-Math III by Oronce and Mendoza, First Edition, 2007
2. The University of Chicago School Mathematics Project
(GEOMETRY) by Usiskin et. al., second Edition, 1997
Web:
1. http://www.mathsisfun.com
2. http://www.mathopenref.com
3. http://www.animatedgif.net
4. http://www.gifs-paradise.com
5. http://classroomclipart.com
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4. Review
Internal and External
Region of a Polygon
Click here to
begin
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5. Internal and External Region of a Polygon
Point G lies on the
A Point F lies on the
Pentagon ABCDE Internal Region of the
Pentagon ABCDE
G
B F E H
The polygon and its
interior region forms the
POLYGONAL REGION. Point H lies on the
Exterior of the
Therefore, points F polygon.
and G lies on the
polygonal region.
C D
ABCDE
PENTAGON (5 – sided polygon)
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6. Discussion
Convex Polygon
Some polygon “bend inwards” while others
The polygons that bend inwards
do not.
are
called “CONCAVE
POLYGON”
and those do not are
called “CONVEX
POLYGON”.
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7. Examples of Convex Polygon
P
E J
A P B
F I
Q
C K
D G H
Q
Q
P
M L
A polygon is considered convex if PQ joining any two
points P and Q lies on the polygonal region.
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8. Examples of Concave Polygon
F K
A Q
B
J
P I
D Q P
E C
G
H
A polygon is considered concave if PQ joining any two
points P and Q lies outside the polygonal region.
A concave polygon is also
known as nonconvex polygon.
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9. Which of the following
polygon is a convex? Activities
Click the figure of your choice.
You’ve got it correctly!
Sorry… Sorry…
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10. Which of the following polygon
is a nonconvex?
Click the figure of your choice.
Amazing……! Sorry… Sorry…
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11. Which of the following figure is
NOT convex nor concave
polygon? Click the figure of your choice.
Sorry… Sorry… Excellent work!
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12. What figure should be placed
on the given figure below to
make it a convex polygon?
Click the figure of your choice. Given
Isosceles
Trapezoid
Sorry…
Excellent work!
Sorry…
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13. Which is/are impossible to construct?
Click the answer of your choice.
Concave equilateral pentagon
Convex irregular 20-gon
Concave trapezoid
Sorry…
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14. Web Links
Click the interactive link on the web for
more interesting activities.
http://www.mathopenref.com/polygonconvex.html
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15. Not everything that can be
counted counts, and not
everything that counts can
be counted.
http://www.coolnsmart.com/math_quotes/
Prepared: Mr. Alvin Patrick Q. Peñaflorida
Division of City Schools - Valenzuela
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