promotion
of
employment,form
a
reasonable
and
orderly
pattern
of
income
distribution,build
a
more
fair
and
sustainable
social
security
systems,medical
and
health
system
reform.The
plenary,innovation
of
social
governance,must
focus
on
the
maintenance
of
fundamental
interests
of
the
overwhelming
majority
of
the
people,maximize
factors,enhance
social
development,improving
social
governance,the
interests
of
national
security,ensure
that
the
people
live
and
work,social
stability
and
order.To
improve
social
governance,stimulating
social
organization,innovative
and
effective
system
of
preventing
and
resolving
social
conflicts,improving
the
public
security
system,set
up
the
National
Security
Council,national
security
systems
and
national
security
strategy
to
ensure
national
security.Plenary
session,the
construction
of
ecological
civilization,you
must
establish
systems
of
ecological
system,using
the
system
to
protect
the
ecological
environment.To
improve
natural
resources
asset
property
right
system
and
use
control,red
line
of
delimitation
of
ecological
protection,resources
paid
use
system
and
ecological
compensation
system
in
ecological
environment
protection
management
system
reform.Plenary
session,centering
on
building
a
listening
party
command,can
win
and
having
a
fine
style
of
the
people
s
army,a
strong
army
under
the
new
situation
of
the
party
Goals,restricting
the
development
of
national
defense
and
army
building
is
solved
outstanding
contradictions
and
problems,innovation
and
development
of
military
theory,enhance
military
strategic
guidance,improve
the
military
strategy
in
the
new
period,building
a
modern
military
force
system
with
Chinese
characteristics.To
deepen
the
adjustment
of
personnel
system
reform
in
the
army,military
policy
and
system
reform,promote
the
development
of
military
and
civilian
integration
depth.Plenary
session
stressed
that
comprehensive
reform
must
be
to
strengthen
and
improve
the
party
s
leadership,give
full
play
to
the
core
role
of
the
party
commands
the
overall
situation
and
coordinating
all
parties,improving
the
party
s
leading
water
.Margin.Challenged
the
leadership
of
the
Communist
Party
of
China,Marxism-Leninism
and
Mao
Zedong
thought
by
Deng
Xiao-ping
s
flag,replaced
by
three
representatives
and
the
harmonic
society.The
former
Communist
Party
spirit
and
social
cohesion
point
of
almost
all
political
makeover.Characteristics
of
socialism
public
ownership
is
shifting
to
private
ownership,planned
regulation
and
market
regulation,the
proletarian
regime
controlled
by
the
elite.Of
universal
equality,fairness
and
basic
principles
of
distribution
system
is
socialist
society,however
after
economic
monopolized
by
powerful,vested
interests
grow,employers
do
not
have
the
same
status,hardly
seems
fair
social
distribution.State
key
protection
of
capital
interests
rather
than
the
interests
of
citizens,had
been
hits
the
bottom
of
the
proletariat
第一次课
1、理解三角形及有关概念，会画任意三角形的高、中线、角平分线；2、了解三角形的稳定性，理解三角形两边的和大于第三边，会根据
三条线段的长度判断它们能否构成三角形；
1、3、会证明三角形内角和
等于180°，了解三角形外角的性质。
2、4、了解多边形的有关概念，会运用多边形的内角和与外角和公式解
3、决问题。
4、5、理解平面镶嵌，知道任意一个三角形、四边形或正六边形可以镶嵌平面，并能运用它们进行简单的平面镶嵌设计
5、[重点难点]
6、一．三角形基本知识
7、1.三角形的有关概念和符号表示，三角形三边间的不等关系是重点；用三角形三边不等关系判定三条线段可否组成三角形是难点
8、三角形的任意两边之和大于第三边.2.三角形的分类：三角形按角可分为锐角三角形、钝角三角形、直角三角形，我们把锐角三角形、钝角三角形统称为斜三角形。
3.三边都相等的三角形叫做等边三角形；
有两条边相等的三角形叫做
等腰三角形；
三边都不相等的三角形叫做不等边三角形。
2．
三角形的高、中线与角平分线是重点；三角形的角平分线与角的
平分线的区别，画钝角三角形的高是难点。
3、三角形的三条中线的交点、三条角平分线的交点在三角形的内
部，而锐三角形的三条高的交点在三角形的内部，直角三角形三
条高的交战在角直角顶点，钝角三角形的三条高的交点在三角形
的外部。
四、三角形的稳定性
5、三角形的内外角和
1、内角和为180°
2、三角形的一个外角等于与它不相邻的两个内角之和。
3、三角形外角的和等于360°。
6、多边形的内外角和
从五边形一个顶点出发可以引______对角线，它们将五边形分成____
三角形，五边形的内角和等于______;
从六边形一个顶点出发可以引_____对角线，它们将六边形分成
____
个三角形，六边形的内角和等于_____;
从n边形一个顶点出发，可以引____对角线，它们将n边形分成____
个三角形，n边形的内角和等于_____。
n边形的内角和等于（n一2）·180°.n边形的外角和等于360°。
从多边形的一个顶点A出发，沿多边形各边走过各顶点，再回到A点，然后转向出发时的方向，在行程中所转的各个角的和就是多边形的外角和，由于走了一周，所得的各个角的和等于一个周角，所以多边形的外角和等于360°
二、回顾与思考
1、什么是三角形？什么是多边形？什么是正多边形？
三角形是不是多边形？
2、什么是三角形的高、中线、角平分线？什么是对角线？
三角形有
对角线吗？n边形的的对角线有多少条？
3、三角形的三条高，三条中线，三条角平分线各有什么特点？
4、三角形的内角和是多少？n边形的内角和是多少？
你能用三角形的内角和说明n边形的内角和吗？
5、三角形的外角和是多少？n边形的外角和是多少？
和普通的声音一样，超声能向一定方向传播，而且可以穿透物体，如果碰到障碍，就会产生回声，不相同的障碍物就会产生不相同的回声，人们通过仪器将这种回声收集并显示在屏幕上，可以用来了解物体的内部结构Obviously,face
China
s
Socialist
system,the
Communist
Party
is
not
the
party.In
that
case,political
chaos
has
been
very
tight.Is
remodeling
or
reconstruction,is
a
correction
or
a
stove.Whether
to
turn
right
or
left,is
back
to
the
source
or
put
forward
new
political
ideas.This
is
to
determine
the
road
problems
in
China,is
also
the
key
out
of
the
deep
water
of
the
reform
of
the
economic
system.After
18,the
new
Central
collective
leadership
attaches
great
importance
to
political
orientation.First,the
“Central
eight
articles“
as
a
starting
point,starting
from
the
Central
Government
s
self-restraint,which
preaches
and
pro-image,brought
fresh
feeling
to
the
community.Secondly,before
reform
and
opening
up
and
reform
and
opening
two
periods
after
non-negative,untying
the
tangle
of
the
society
a
long
time
on
this
issue.Third,a
new
generation
of
party
leaders
on
various
occasions
to
Mao
Ze-Dong
and
Mao
Ze-Dong
s
thought
of
evaluation
has
room
for
manoeuvre,through
to
the
ruling
ideology
of
Mao
Zedong
thought,is
the
call
of
the
soul
to
the
Socialist
Revolution
and
construction.Empty
talks
jeopardize
national
interests
and
try
again,is
an
affirmation
of
Deng
Xiao-ping
s
reform
ideas.These
strong
political
signal
showing
a
new
generation
of
political
leaders
is
still
keeping
to
the
Socialist
road.Four
is
revisiting
the
“talking
to
Mao
Ze-Dong
s
historical
cycle
of“
high
profile
anti-corruption
and
the
importance
of
the
Constitution,reorganization
is
bad
style
of
officialdom,was
to
civilize
people
obey
the
law,while
improving
the
color
change
of
the
regime
of
vigilance.Five
is
to
reform
into
deeper
waters
and
stressed
that
top-level
design,this
is
a
review
on
the
reform
and
opening
up
in
the
past,is
also
looking
for
a
way
out.Six
foreign
and
Russia
closer,the
flexible
attitude
on
the
issue
of
the
Korean
peninsula,Sino-Japanese
fishing
hardline
China
on
the
island
out
of
the
“patient“
and
low
profile
shadow
began
to
gradually
plan
development.Signs
show
that
the
new
leadership
began
to
make
a
left
turn
in
politics.However,as
of
right
now,not
only
ideological
confusion
in
the
community,the
new
leadership
s
thinking
is
messy.New
leaders
both
stressed
the
need
to
implement
the
Constitution,stressed
the
need
to
turn
off
the
power
in
a
cage.Also
stresses
that
Mao
Zedong
thought
cannot
be
lost,30
years
after
the
reform
and
opening
up
30
years
ago
can
not
deny
each
other.Both
advocate
democracy
and
release
“seven
does
not
speak
of“
files
of
political
constraints.Neither
deny
the
history
of
the
CPC
Central
Committee
on
several
issues
.Comrades:
today
brings
together
members,mainly
in
order
to
provide
a
platform
to
Exchange
and
learn
from
each
other
in
order
to
facilitate
our
work.Just
now,we
focus
on
taxation,planning
and
stability,safety,project
construction,typical
topics
such
as
private
facts
presentation
and
interaction,and
towns
currently
exist
in
the
in-depth
analysis
of
the
problems
to
be
solved,to
explore
new
methods
to
solve
the
problem.It
can
be
said
that
summing
up
the
achievement,no
grandstanding;
analysis