11 X1 T07 01 angle theorems (2010)

61
Euclidean Geometry

Transcript of 11 X1 T07 01 angle theorems (2010)

Page 1: 11 X1 T07 01 angle theorems (2010)

Euclidean Geometry

Page 2: 11 X1 T07 01 angle theorems (2010)

Euclidean GeometryGeometry DefinitionsNotation

toparallelis ||

Page 3: 11 X1 T07 01 angle theorems (2010)

Euclidean GeometryGeometry DefinitionsNotation

toparallelis || lar toperpendicuis

Page 4: 11 X1 T07 01 angle theorems (2010)

Euclidean GeometryGeometry DefinitionsNotation

toparallelis || lar toperpendicuis tocongruent is

Page 5: 11 X1 T07 01 angle theorems (2010)

Euclidean GeometryGeometry DefinitionsNotation

toparallelis || lar toperpendicuis tocongruent is

similar tois |||

Page 6: 11 X1 T07 01 angle theorems (2010)

Euclidean GeometryGeometry DefinitionsNotation

toparallelis || lar toperpendicuis tocongruent is

similar tois |||

therefore

Page 7: 11 X1 T07 01 angle theorems (2010)

Euclidean GeometryGeometry DefinitionsNotation

toparallelis || lar toperpendicuis tocongruent is

similar tois |||

therefore because

Page 8: 11 X1 T07 01 angle theorems (2010)

Euclidean GeometryGeometry DefinitionsNotation

Terminology

toparallelis || lar toperpendicuis tocongruent is

similar tois |||

therefore because

produced – the line is extended

Page 9: 11 X1 T07 01 angle theorems (2010)

Euclidean GeometryGeometry DefinitionsNotation

Terminology

toparallelis || lar toperpendicuis tocongruent is

similar tois |||

therefore because

produced – the line is extended

X YXY is produced to A

A

Page 10: 11 X1 T07 01 angle theorems (2010)

Euclidean GeometryGeometry DefinitionsNotation

Terminology

toparallelis || lar toperpendicuis tocongruent is

similar tois |||

therefore because

produced – the line is extended

X YXY is produced to A

A

YX is produced to B

B

Page 11: 11 X1 T07 01 angle theorems (2010)

Euclidean GeometryGeometry DefinitionsNotation

Terminology

toparallelis || lar toperpendicuis tocongruent is

similar tois |||

therefore because

produced – the line is extended

X YXY is produced to A

A

YX is produced to B

B

foot – the base or the bottom

Page 12: 11 X1 T07 01 angle theorems (2010)

Euclidean GeometryGeometry DefinitionsNotation

Terminology

toparallelis || lar toperpendicuis tocongruent is

similar tois |||

therefore because

produced – the line is extended

X YXY is produced to A

A

YX is produced to B

B

foot – the base or the bottomA

B

CD

B is the foot of the perpendicular

Page 13: 11 X1 T07 01 angle theorems (2010)

Euclidean GeometryGeometry DefinitionsNotation

Terminology

toparallelis || lar toperpendicuis tocongruent is

similar tois |||

therefore because

produced – the line is extended

X YXY is produced to A

A

YX is produced to B

B

foot – the base or the bottomA

B

CD

B is the foot of the perpendicular

collinear – the points lie on the same line

Page 14: 11 X1 T07 01 angle theorems (2010)

Euclidean GeometryGeometry DefinitionsNotation

Terminology

toparallelis || lar toperpendicuis tocongruent is

similar tois |||

therefore because

produced – the line is extended

X YXY is produced to A

A

YX is produced to B

B

foot – the base or the bottomA

B

CD

B is the foot of the perpendicular

collinear – the points lie on the same lineconcurrent – the lines intersect at the same

point

Page 15: 11 X1 T07 01 angle theorems (2010)

Euclidean GeometryGeometry DefinitionsNotation

Terminology

toparallelis || lar toperpendicuis tocongruent is

similar tois |||

therefore because

produced – the line is extended

X YXY is produced to A

A

YX is produced to B

B

foot – the base or the bottomA

B

CD

B is the foot of the perpendicular

collinear – the points lie on the same lineconcurrent – the lines intersect at the same

pointtransversal – a line that cuts two(or more)

other lines

Page 16: 11 X1 T07 01 angle theorems (2010)

Naming ConventionsAngles and Polygons are named in cyclic order

Page 17: 11 X1 T07 01 angle theorems (2010)

Naming ConventionsAngles and Polygons are named in cyclic order

A

B C

CBAABC ˆor

BB ˆor

ambiguity no If

Page 18: 11 X1 T07 01 angle theorems (2010)

Naming ConventionsAngles and Polygons are named in cyclic order

A

B C

CBAABC ˆor

BB ˆor

ambiguity no IfP

V

T

QVPQT or QPVT or QTVP etc

Page 19: 11 X1 T07 01 angle theorems (2010)

Naming ConventionsAngles and Polygons are named in cyclic order

A

B C

CBAABC ˆor

BB ˆor

ambiguity no IfP

V

T

QVPQT or QPVT or QTVP etc

Parallel Lines are named in corresponding order

Page 20: 11 X1 T07 01 angle theorems (2010)

Naming ConventionsAngles and Polygons are named in cyclic order

A

B C

CBAABC ˆor

BB ˆor

ambiguity no IfP

V

T

QVPQT or QPVT or QTVP etc

Parallel Lines are named in corresponding order

A

B

C

D

AB||CD

Page 21: 11 X1 T07 01 angle theorems (2010)

Naming ConventionsAngles and Polygons are named in cyclic order

A

B C

CBAABC ˆor

BB ˆor

ambiguity no IfP

V

T

QVPQT or QPVT or QTVP etc

Parallel Lines are named in corresponding order

A

B

C

D

AB||CD

Equal Lines are marked with the same symbol

Page 22: 11 X1 T07 01 angle theorems (2010)

Naming ConventionsAngles and Polygons are named in cyclic order

A

B C

CBAABC ˆor

BB ˆor

ambiguity no IfP

V

T

QVPQT or QPVT or QTVP etc

Parallel Lines are named in corresponding order

A

B

C

D

AB||CD

Equal Lines are marked with the same symbol

P

Q R

S

PQ = SRPS = QR

Page 23: 11 X1 T07 01 angle theorems (2010)

Constructing ProofsWhen constructing a proof, any line that you state must be one of the following;

Page 24: 11 X1 T07 01 angle theorems (2010)

Constructing ProofsWhen constructing a proof, any line that you state must be one of the following;

1. Given information, do not assume information is given, e.g. if you are told two sides are of a triangle are equal don’t assume it is isosceles, state that it is isosceles because two sides are equal.

Page 25: 11 X1 T07 01 angle theorems (2010)

Constructing ProofsWhen constructing a proof, any line that you state must be one of the following;

1. Given information, do not assume information is given, e.g. if you are told two sides are of a triangle are equal don’t assume it is isosceles, state that it is isosceles because two sides are equal.

2. Construction of new lines, state clearly your construction so that anyone reading your proof could recreate the construction.

Page 26: 11 X1 T07 01 angle theorems (2010)

Constructing ProofsWhen constructing a proof, any line that you state must be one of the following;

1. Given information, do not assume information is given, e.g. if you are told two sides are of a triangle are equal don’t assume it is isosceles, state that it is isosceles because two sides are equal.

2. Construction of new lines, state clearly your construction so that anyone reading your proof could recreate the construction.

3. A recognised geometrical theorem (or assumption), you must state clearly the theorem you are using

Page 27: 11 X1 T07 01 angle theorems (2010)

Constructing ProofsWhen constructing a proof, any line that you state must be one of the following;

1. Given information, do not assume information is given, e.g. if you are told two sides are of a triangle are equal don’t assume it is isosceles, state that it is isosceles because two sides are equal.

2. Construction of new lines, state clearly your construction so that anyone reading your proof could recreate the construction.

3. A recognised geometrical theorem (or assumption), you must state clearly the theorem you are using

180sum 18012025e.g. A

Page 28: 11 X1 T07 01 angle theorems (2010)

Constructing ProofsWhen constructing a proof, any line that you state must be one of the following;

1. Given information, do not assume information is given, e.g. if you are told two sides are of a triangle are equal don’t assume it is isosceles, state that it is isosceles because two sides are equal.

2. Construction of new lines, state clearly your construction so that anyone reading your proof could recreate the construction.

3. A recognised geometrical theorem (or assumption), you must state clearly the theorem you are using

4. Any working out that follows from lines already stated.

180sum 18012025e.g. A

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Angle Theorems

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Angle Theorems180 toup add linestraight ain Angles

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Angle TheoremsA B C

D 180 toup add linestraight ain Anglesx 30

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Angle TheoremsA B C

D 180 toup add linestraight ain Angles

180straight 18030 ABCxx 30

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Angle TheoremsA B C

D 180 toup add linestraight ain Angles

180straight 18030 ABCx150x

x 30

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Angle TheoremsA B C

D 180 toup add linestraight ain Angles

180straight 18030 ABCx150x

x 30

equalareanglesopposite Vertically

Page 35: 11 X1 T07 01 angle theorems (2010)

Angle TheoremsA B C

D 180 toup add linestraight ain Angles

180straight 18030 ABCx150x

x 30

equalareanglesopposite Vertically

x3 39

Page 36: 11 X1 T07 01 angle theorems (2010)

Angle TheoremsA B C

D 180 toup add linestraight ain Angles

180straight 18030 ABCx150x

x 30

equalareanglesopposite Vertically

ares'oppositevertically 393xx3 39

Page 37: 11 X1 T07 01 angle theorems (2010)

Angle TheoremsA B C

D 180 toup add linestraight ain Angles

180straight 18030 ABCx150x

x 30

equalareanglesopposite Vertically

ares'oppositevertically 393x13x

x3 39

Page 38: 11 X1 T07 01 angle theorems (2010)

Angle TheoremsA B C

D 180 toup add linestraight ain Angles

180straight 18030 ABCx150x

x 30

equalareanglesopposite Vertically

ares'oppositevertically 393x13x

x3 39

360 equalpoint aabout Angles

Page 39: 11 X1 T07 01 angle theorems (2010)

Angle TheoremsA B C

D 180 toup add linestraight ain Angles

180straight 18030 ABCx150x

x 30

equalareanglesopposite Vertically

ares'oppositevertically 393x13x

x3 39

360 equalpoint aabout Anglesy

15150

120

Page 40: 11 X1 T07 01 angle theorems (2010)

Angle TheoremsA B C

D 180 toup add linestraight ain Angles

180straight 18030 ABCx150x

x 30

equalareanglesopposite Vertically

ares'oppositevertically 393x13x

x3 39

360 equalpoint aabout Angles

360revolution 36012015015 yy15

150120

Page 41: 11 X1 T07 01 angle theorems (2010)

Angle TheoremsA B C

D 180 toup add linestraight ain Angles

180straight 18030 ABCx150x

x 30

equalareanglesopposite Vertically

ares'oppositevertically 393x13x

x3 39

360 equalpoint aabout Angles

360revolution 36012015015 y75y

y15

150120

Page 42: 11 X1 T07 01 angle theorems (2010)

Parallel Line Theoremsa b

c d

efh

g

Page 43: 11 X1 T07 01 angle theorems (2010)

Parallel Line Theoremsa b

c d

efh

g

Alternate angles (Z) are equal

Page 44: 11 X1 T07 01 angle theorems (2010)

Parallel Line Theoremsa b

c d

efh

g

Alternate angles (Z) are equal

lines||,s'alternate fc

Page 45: 11 X1 T07 01 angle theorems (2010)

Parallel Line Theoremsa b

c d

efh

g

Alternate angles (Z) are equal

lines||,s'alternate fced

Page 46: 11 X1 T07 01 angle theorems (2010)

Parallel Line Theoremsa b

c d

efh

g

Alternate angles (Z) are equal

lines||,s'alternate fced

Corresponding angles (F) are equal

Page 47: 11 X1 T07 01 angle theorems (2010)

Parallel Line Theoremsa b

c d

efh

g

Alternate angles (Z) are equal

lines||,s'alternate fced

Corresponding angles (F) are equal

lines||,s'ingcorrespond ea

Page 48: 11 X1 T07 01 angle theorems (2010)

Parallel Line Theoremsa b

c d

efh

g

Alternate angles (Z) are equal

lines||,s'alternate fced

Corresponding angles (F) are equal

lines||,s'ingcorrespond eafb gc hd

Page 49: 11 X1 T07 01 angle theorems (2010)

Parallel Line Theoremsa b

c d

efh

g

Alternate angles (Z) are equal

lines||,s'alternate fced

Corresponding angles (F) are equal

lines||,s'ingcorrespond eafb gc hd

Cointerior angles (C) are supplementary

Page 50: 11 X1 T07 01 angle theorems (2010)

Parallel Line Theoremsa b

c d

efh

g

Alternate angles (Z) are equal

lines||,s'alternate fced

Corresponding angles (F) are equal

lines||,s'ingcorrespond eafb gc hd

Cointerior angles (C) are supplementary

lines||,180s'cointerior 180 ec

Page 51: 11 X1 T07 01 angle theorems (2010)

Parallel Line Theoremsa b

c d

efh

g

Alternate angles (Z) are equal

lines||,s'alternate fced

Corresponding angles (F) are equal

lines||,s'ingcorrespond eafb gc hd

Cointerior angles (C) are supplementary

lines||,180s'cointerior 180 ec180 fd

Page 52: 11 X1 T07 01 angle theorems (2010)

e.g. A B

C D

P

Qx

y65

120

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e.g. A B

C D

P

Qx

y65

120

180straight 18065 CQDx

Page 54: 11 X1 T07 01 angle theorems (2010)

e.g. A B

C D

P

Qx

y65

120

180straight 18065 CQDx115x

Page 55: 11 X1 T07 01 angle theorems (2010)

e.g. A B

C D

P

Qx

y65

120

180straight 18065 CQDx115x

Construct XY||CD passing through P

X Y

Page 56: 11 X1 T07 01 angle theorems (2010)

e.g. A B

C D

P

Qx

y65

120

180straight 18065 CQDx115x

Construct XY||CD passing through P

X Y

QXYXPQ C||,s'alternate 65

Page 57: 11 X1 T07 01 angle theorems (2010)

e.g. A B

C D

P

Qx

y65

120

180straight 18065 CQDx115x

Construct XY||CD passing through P

X Y

QXYXPQ C||,s'alternate 65

XYABXPB ||,180s'cointerior 180120

Page 58: 11 X1 T07 01 angle theorems (2010)

e.g. A B

C D

P

Qx

y65

120

180straight 18065 CQDx115x

Construct XY||CD passing through P

X Y

QXYXPQ C||,s'alternate 65

XYABXPB ||,180s'cointerior 180120 60XPB

Page 59: 11 X1 T07 01 angle theorems (2010)

e.g. A B

C D

P

Qx

y65

120

180straight 18065 CQDx115x

Construct XY||CD passing through P

X Y

QXYXPQ C||,s'alternate 65

XYABXPB ||,180s'cointerior 180120 60XPB

common XPBXPQBPQ

Page 60: 11 X1 T07 01 angle theorems (2010)

e.g. A B

C D

P

Qx

y65

120

180straight 18065 CQDx115x

Construct XY||CD passing through P

X Y

QXYXPQ C||,s'alternate 65

XYABXPB ||,180s'cointerior 180120 60XPB

common XPBXPQBPQ

1256065

yy

Page 61: 11 X1 T07 01 angle theorems (2010)

e.g.

Book 2Exercise 8A;1cfh, 2bdeh,3bd, 5bcf,6bef, 10bd,11b, 12bc,

13ad, 14, 15

A B

C D

P

Qx

y65

120

180straight 18065 CQDx115x

Construct XY||CD passing through P

X Y

QXYXPQ C||,s'alternate 65

XYABXPB ||,180s'cointerior 180120 60XPB

common XPBXPQBPQ

1256065

yy