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Angle facts. P. R. ^. ^. PQR. and. RQS. Add up to 90 º. Two angles which make a RIGHT angle are. a º. COMPLEMENTARY. b º. a º is the complement of b º. Q. S. and b º is the complement of a º. a º + b º = 90 º. - PowerPoint PPT Presentation
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Angle facts
a º
b º
a º is the complement of b º
P
Q
R
S
^PQR and
^RQS Add up to 90 º
Two angles which make a RIGHT angle are
COMPLEMENTARY
and b º is the complement of a º
a º + b º = 90 º
the complements of the following angles are
10 º
50 º
35 º
17 º
81 º
45 º
36 º
57 º
6 º
A
B C
Dthe complement of < DBC is
E
< EBC = 72 º the size of <DBC is
the size of <ABD is
80 º
40 º
55 º
73 º
9 º
45 º
54 º
33 º
84 º
<ABD or
<EBC
18 º
72 º
Supplementary angles
E F G
H
p º q º
<EFH and <HFG add up to 180 º
Two angles which make a STRAIGHT angle
are
SUPPLEMENTARY
a º is the supplement of b º
and b º is supplement of a º
p º + q º = 180 º
the supplements of the following angles are
60 º 130 º 5 º
100 º 168 º 55 º
178 º 45 º 90 º
120 º
80 º
2 º
50 º
12 º
135 º
175 º
125 º
90 º
A
B
C
D
E
The supplement of <AED is
The supplement of <CED is
<AED IS140 º <AEB is
<DEC is 75 º <BEC is
<ABC
<CEB
40 º
105 º
Vertically opposite angles
A B
CD
Vertically opposite angles are found on opposite sides of a vertex
< AEB IS VERTICALLY OPPOSITE <DEC
< AED IS VERTICALLY OPPOSITE <BEC
E
To find vertically opposite angles we
look for angles in an X shape
aº
bº
bº + aº = 180º
cº
bº + cº = 180º
aº must be equal to cº
<AEB and <DEC are vertically opposite angles
vertically opposite angles are equal
A
B
CD
E
Another pair of vertically opposite angles are
<AED and <BEC
Corresponding angles
A
BC
D E
FAngles ABC and ADE are
CORRESPONDING ANGLES
They are in the same position and they are equal
BC and DE are parallel lines
P
Q
R
T
S
An angle corresponding to <PQR is <TRS
x
x
1
2
34
5
67
8
An angle corresponding to
1 is
2 is
6 is
5 is
5
3
4
7Ex4a 1-4
This grid is made up two sets of parallel lines
>>>
>>>> >
>
>
>The red shape between the lines is a parallelogram
The parallelogram can slide along and down the grid
All the parallelograms in the grid are
All the blue angles in the same position and are equal
CONGRUENT
Equal angles in the same position are called
CORRESPONDING ANGLES
Find all the angles corresponding to the blue angle
To find corresponding angles we look for F
shapes
x
x
x
Copy the diagrams.Mark the angles which are corresponding to the given ones with an x
x
Alternate angles
A
BC
D E
FAngles CBG and BGD are
ALTERNATE ANGLES
They are on opposite sides of the transverse line AF found between the parallel lines
BC and DE are parallel linesG
c =100º
a
b
a= a is vertically opposite c
b= b is corresponding to a
b is alternate to c b = c
ALTERNATE ANGLES ARE EQUAL
= 100 º
100 º
100 º
Q
R
T
S
An angle alternate to <PQR is <QRT
x
x
1
2
34
5
67
8
An angle ALTERNATE to
7 is
3 is
6
8
p
To find ALTERNATE angles we look for Z
shapes
x
x
x
x
Copy the diagrams Mark the angles which are alternate to the given ones with an x
