11. Naming Polygon and its Parts
A polygon is named using its vertices. The vertices are
points A, B, and C. So, the triangle may be called triangle
ABC, triangle BCA, or triangle ACB.
Sides of triangle ABC are AB ,BC, AC
Interior angles of triangle ABC are BAC, BCA, and
∠ ∠
ABC
∠
12. For Naming Polygon and its parts:
• Polygons may be named based on the number of sides.
Triangle- it has 3 sides – “tri”
Qudrilateral- has 4 sides – “quad”
Pentagon – has 5 sides – “penta”
Hexagon – has 6 sides –”hexa”
Heptagon – has 7 sides – “hexa”
Octagon – has 8 sides –”octa”
Nonagon – has 9 sides – “nona”
Decagon – has 10 sides – “deca”
14. DAY 2
Name, describe, and compare regular and
irregular polygons with 5, 6, 8, or 10 sides
based on measurements of sides and angles
15. A square has 4 sides. A square has 4 equal
sides. All interior angles of a square are equal to
90 degrees.
• Square is one of the regular polygons.
• What do you think is special in square that
makes it regular
polygon?
16. Regular and Irregular Polygons
• Regular polygon is a polygon that is
both equilateral and equiangular.
• Irregular polygon is a polygon whose
sides and angles are not equal.
17. The markings mean the same measures of sides
and the other marking in blue means that the
measure of each angle is 90 degrees.
18. Measure of each interior angles:
Regular Pentagon Regular Hexagon Regular Octagon Regular decagon
108° each 120° each 135° each 144° each
the sum of the interior angles:
for regular and
irregular
pentagon
for regular and
irregular
hexagon
for regular and
irregular
octagon
for regular and
irregular
decagon
540° 720° 1080° 1,440°
19. DAY 3 -4
Draw polygons with 5, 6, 8, or 10 sides
using a ruler, protractor, and a compass.
20. Quiz Bee:
1. What do you call a polygon with 6 sides?
HEXAGON
2. What is the sum of the interior angles of
an octagon?
1080°
3. A polygon has 10 sides. What is it called?
DECAGON
21. 4. What is a polygon called if all its sides and
angles are equal?
REGULAR POLYGON
5. What is the measure of each interior angle of
a regular hexagon?
120°
6. What do you call a polygon with 8 sides?
OCTAGON
22. 7. What do you call a polygon with 5 sides?
PENTAGON
8. A polygon has 4 sides. What is it called and how
is it classified if all sides and angles are equal?
Quadrilateral, Regular
(specifically a Square)
9. What do you call a polygon with 7 sides?
PENTAGON
23. Activity 3: Drawing Polygons
Instructions: Draw each polygon
using your ruler, protractor,
and compass.
