Transcript Classifying Polygons

Classifying Polygons
What is a polygon?
Definition: Closed plane figure with at least
three sides
Sides only meet at their endpoints (called
vertices)
Regular polygons have all sides and
angles congruent
Classifying Polygons
NAME
TRIANGLE
# OF
SIDES
# OF
DIAGONALS
SUM OF
INTERIOR
ANGLES
EACH ANGLE
3
0
180°
60°
QUADRILATERAL 4
2
360°
90°
PENTAGON
5
5
540°
108°
HEXAGON
6
9
720°
120°
SEPTAGON/
HEPTAGON
7
OCTAGON
8
NONAGON
9
DECAGON
10
What is the rule for regular polygons?
Any polygon with sides n:
Sum of interior angles formula:(n-2) × 180°
Each angle formula: (n-2) × 180° / n
How are triangles classified?
Acute- three acute angles (less than 90°)
Right- one right angle
Obtuse- one obtuse angle (more than 90°)
Equilateral- three congruent sides
Isosceles- two congruent sides
Scalene- no congruent sides
How are quadrilaterals classified?
Trapezoid- one pair of parallel sides
Parallelogram- both pairs of opposite
sides are parallel
Rhombus- four congruent sides
Rectangle- four right angles
Square- four right angles and four
congruent sides