Download Discovering Geometry Day 4

Discovering Geometry
Day 4
1.4 Polygons
 Daily Openers
 Check and go over homework
 Quiz (Sections 1.1-1.3)
1.4 Polygons
polygon – a closed planar figure, formed by connecting segments endpoint to endpoint with each
segment intersecting exactly two others.
side – each segment of the polygon.
vertex – the point where two sides meet.
Polygons
Not Polygons
Sides
Name
3
Triangle
4
Quadrilateral
5
Pentagon
6
Hexagon
7
Heptagon
8
Octagon
9
Nonagon
10
Decagon
11
Undecagon
12
Dodecagon
n
n-gon
convex – each line containing a side has no points on interior of the polygon.
concave – a line containing a side of the polygon contains a point on the interior
of the polygon.
Ex. Classify each:
(a)
(b)
(c)
diagonal – a segment that joins two non-consecutive vertices.
congruent polygons – two polygons that are exactly the same size and shape.
perimeter – the sum of the lengths of the sides of a polygon.
equilateral polygon – a polygon with all side lengths congruent.
equiangular polygon – a polygon with all angle measures congruent.
regular polygon – a polygon that is both equilateral and equiangular.
Homework – pages 56–58 #1–24
Daily Openers – 1. Describe the difference between supplementary angles and a linear pair.
2. Simplify: (a) 75
(b) 4 160
3. Simplify:
3 8
4 15
4. Find the slope of the line: 40x – 64y + 8 = 0
5. What is the (a) complement and (b) supplement of a 27˚ angle?