Download Geometry A Unit 7 Day 1 Polygons and Angle Sums I. Vocabulary A

Geometry A Unit 7 Day 1
Polygons and Angle Sums
I. Vocabulary
A. Polygon - Any figure with these properties…
1. Each side is a line segment. (No curves allowed)
2. Sides meet only at the endpoints. (Sides can’t cross)
3. The figure is a closed figure. (There is a clear interior and exterior, since every
side meets two other sides.)
1. Determine whether the figures are polygons. If you answer “NO” explain your
reasoning.
a.
b.
YES
or NO
(circle one)
YES
or NO
(circle one)
If NO, why not? _________________
If NO, why not? _________________
_______________________________
_______________________________
c.
d.
YES
or NO
(circle one)
YES
or NO
(circle one)
If NO, why not? _________________
If NO, why not? _________________
_______________________________
_______________________________
2. Which of the following is NOT a polygon?
a.
b.
c
d
B. Words used to describe polygons (NOT JUST TRIANGLES).
1. Equilateral – All sides are equal
2. Equiangular – All angles are equal
3. Regular – A word that indicates a figure is both equilateral and equiangular.
a. Unlike a triangle, where equal sides
imply equal angles…
...polygons with more sides can be equilateral but not equiangular or
vice versa.
Place the word EQUILATERAL or EQUIANGULAR in each blank.
The rectangle on the left is
Q:
The rhombus on the right is
______________, but not
______________, but not
_____________________
_____________________
Which figure above is regular?
A. The Rectangle
B. The Rhombus
C. Both
D. Neither
C. Diagonal – A segment connecting two non-consecutive corners of a polygon.
The dotted lines represent all of the diagonals that can be drawn from point A.
A
D. Words telling us about the shape of a polygon.
1. Concave – A polygon in which at least one diagonal is located outside of the
figure.
Each of the following polygons are CONCAVE.
Write a less formal, but simpler definition for concave.
1. Concave - ___________________________________________________________
__________________________________________________________________.
2. Convex – A polygon that is not concave.
Each of the following polygons are CONVEX.
Ex: Determine whether each figure is:
a) NOT A POLYGON
b) A CONCAVE POLYGON
c) A CONVEX POLYGON
1) ______
2) _____
3) _____
4) ______
5) _____
6) _____
D. Words telling us the number of sides on a polygon. The chart below gives the names
of polygons based on their number of sides.
Number of sides
3
4
5
6
7
Type of polygon
Triangle
Quadrilateral
Pentagon
Hexagon
Heptagon
Number of sides
8
9
10
12
n
Type of polygon
Octagon
Nonagon
Decagon
Dodecagon
n-gon