Ch 4 Notesheet Key

Ch 4 Note Sheet L1 Key
Name ___________________________
What do you need to know to get…
You’ll need Equal Segments to get…
Def. Isosceles Triangle
If a triangle’s legs are congruent,
then it is isosceles.
If VB
then
≅ VS
ΔVBS
isosceles.
B
V
S
Def. Median
If a segment connects the vertex to the
midpoint of the opposite side,
then it is a median.
If BM ≅ MC ,
then AM is median in
A
Δ ABC .
B
M
C
Def. Midpoint
S
If a point divides the segment into
two equal segments,
then it is a midpoint.
If SM ≅ MG ,
then M is the midpoint of SG .
M
G
Def. segment bisector
C
If a line (or part of a line) passes through the
midpoint of the segment,
then it is a bisector.
M
If AM ≅ MB,
A
then CM bisects AB .
B
You’ll need Equal Angles to get…
Converse of the Isosceles Triangle Conj.
If a triangle has two congruent angles,
then it is an isosceles triangle. V S
If ∠B ≅ ∠ S ,
ΔVBS
then
isosceles.
B
Def. perpendicular lines
If two lines intersect to form equal
adjacent angles,
then they are perpendicular.
If m∠ CMA= m∠ CMB ,
⊥ AB .
then CD
C
A
M
B
D
Definition of Angle Bisector
If a ray cuts the angle into two
equal angles, then you have
an angle bisector.
If ∠ABD ≅ ∠ DBC ,
ABC
then BD bisects ∠ .
B
C
A
D
Corresponding Angles Conjecture
If two lines are cut by a transversal and
the corresponding angles are congruent,
then the lines are parallel.
If ∠EFA ≅∠ FGD ,
DC
then AB .
A
D
G
E
F
B
C
Def. Altitude
If a segment goes from a vertex
perpendicular to the line that
contains the opposite side,
then it is an altitude.
If m∠ RAT = m∠ RAI = 90°,
TRI
then RA is an altitude of
T
R
A
Δ .
I
Alternate Interior Angles Conjecture
If two lines are cut by a transversal and
the alternate interior angles are congruent,
then the lines are parallel.
If ∠KHM ≅∠ HMN ,
NJ
then LK
.
L
N
M
H
K
J
S. Stirling Page 13 of 15