Download 7.2inclassnotes - Barrington 220

7.2inclass
Geometry chapter 7, Polygons, section 7.1
The sum of the measures of the angles of a triangle
is equal to 180 degrees.
Definition: An exterior angle of a polygon is an angle that is
adjacent to and supplementary to an interior angle of a
polygon. It is formed by extending one of the sides of the
polygon to the exterior.
The measure of an exterior angle of a triangle is equal to the
sum of the measures of the two remote interior angles. Th 51
The segment joining the midpoints of two sides of a
triangle is parallel to the third side and its length is onehalf the length of the third side.
The Midline theorem Th 52
December 04, 2015
7.2inclass
December 04, 2015
35
80
x
z
70
y
45
7.2inclass
December 04, 2015
7.2inclass
7.2 Two-Proof oriented triangle theorems
If two angles of one triangle are congruent to two
angles of another triangle, then then the third angles
are congruent.
NO Choice theorem Th 53
If there exists a correspondence between the
vertices of two triangles such that two angles and
a non-included side of one triangle are congruent
to the corresponding parts of the other triangle,
then the triangles are congruent. AAS Th 54
December 04, 2015
7.2inclass
December 04, 2015
D
G: DC m,
<DAC <DBC
P: <BAC <ABC
m
C
A
B
Z
G: AC // XY, AB // CY
<ZAC <XAB
P: < X < Z
C
A
X
B
Y
7.2inclass
December 04, 2015
7.2inclass
December 04, 2015
N
<N=40 deg.
PR and SR are
angle bisectors.
NP = NS
Find measure of
<R
R
P
S
B
A
C
BD=DG, <ADG = 28 deg,
F, G, C are collinear
G
Find measures of
<GBD_____ <ACG_______
<AGB_____ <FGE________
<CGD_____ <BGC________
F
E
D
7.2inclass
December 04, 2015
7.2inclass
December 04, 2015
7.2inclass
December 04, 2015
if EQUIA
#
#
sides triangles
nx180 sum
each
angle
7.2inclass
December 04, 2015
7.2-7.3 Formulas involving Polynomials
7.2inclass
December 04, 2015