1. 8.5 Classifying Polygons

2. Understanding Polygons and Regular Polygons
Polygon - A closed figure with at least 3 sides.
Regular Polygon - Polygon with ALL sides congruent
and ALL angles congruent.
Polygons
Regular Polygons
# of sides
Name
Drawing
Drawing
Name
Acute
Equilateral 3
Triangle 4
Quadrilateral
Square
Regular
Pentagon 5
Pentagon
Regular
Hexagon 6
Hexagon

3. Classifying Triangles
Name
Acute
- All angles
less than 90 .
Right
- Only One
angle equal to 90 .
Obtuse
- Only One
angle more than 90 .
Side
Name
- All
three sides equal.
Equilateral
Isosceles
- Two
sides equal.
Scalene
- No
equal sides.

4. Angles of a Triangle
Every triangle has angles whose sum equals 180 . a b c
Solve for x. x

5. Classifying Quadrilaterals

6. Quadrilateral
A closed figure with four sides that are line segments
Parallelogram
A quadrilateral with two sets of parallel sides
Rectangle
A quadrilateral with two sets of parallel sides and four right angles
Square
A quadrilateral with two sets of parallel sides, four right angles, and all sides congruent
Rhombus
A quadrilateral with two sets of parallel sides and all sides congruent
Trapezoid
A quadrilateral with only one set of parallel sides
Isosceles Trapezoid
A quadrilateral with only one set of parallel sides and a pair of nonparallel sides congruent
Kite
A quadrilateral with no parallel sides, but with two pairs of sides congruent

7. Understanding Quadrilaterals
A quadrilateral…
With TWO pairs of parallel lines
With ONE pair of parallel lines
With ZERO pairs of parallel lines
…and two pairs of congruent sides
…and a pair of non-parallel sides congruent
…and four right angles
…and all sides congruent
…and all sides congruent

10. Homework
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