Transcript

Tangent Theorems

Tangent Theorems(7) Assumption:

The size of the angle between a tangent and the radius drawn to the point of contact is 90 degrees.

Tangent Theorems(7) Assumption:

The size of the angle between a tangent and the radius drawn to the point of contact is 90 degrees.

tangentradius XYOX

Tangent Theorems(7) Assumption:

The size of the angle between a tangent and the radius drawn to the point of contact is 90 degrees.

tangentradius XYOX

Let x be the distance of the chord from the centre.

xO X

Y

Z

Tangent Theorems(7) Assumption:

The size of the angle between a tangent and the radius drawn to the point of contact is 90 degrees.

tangentradius XYOX

Let x be the distance of the chord from the centre.

y

xLet 2y be the length of the chord.

y

O X

Y

Z

Tangent Theorems(7) Assumption:

The size of the angle between a tangent and the radius drawn to the point of contact is 90 degrees.

tangentradius XYOX

Let x be the distance of the chord from the centre.

y

xLet 2y be the length of the chord.

y

O X

Y

Z

chord tomidpoint,

tocentre joining line YZOX

Tangent Theorems(7) Assumption:

The size of the angle between a tangent and the radius drawn to the point of contact is 90 degrees.

tangentradius XYOX

Let x be the distance of the chord from the centre.

y

xLet 2y be the length of the chord.

y

O X

Y

Z

chord tomidpoint,

tocentre joining line YZOX

0y

radius As

x

Tangent Theorems(7) Assumption:

The size of the angle between a tangent and the radius drawn to the point of contact is 90 degrees.

tangentradius XYOX

Let x be the distance of the chord from the centre.

y

O xLet 2y be the length of the chord.

y

X

Y

Z

chord tomidpoint,

tocentre joining line YZOX

0y

radius As

x

Tangent Theorems(7) Assumption:

The size of the angle between a tangent and the radius drawn to the point of contact is 90 degrees.

tangentradius XYOX

Let x be the distance of the chord from the centre.

yO x

Let 2y be the length of the chord.

yX

Y

Z

chord tomidpoint,

tocentre joining line YZOX

0y

radius As

x

Tangent Theorems(7) Assumption:

The size of the angle between a tangent and the radius drawn to the point of contact is 90 degrees.

tangentradius XYOX

Let x be the distance of the chord from the centre.

O xLet 2y be the length of the chord.

X

Y

Z

chord tomidpoint,

tocentre joining line YZOX

0y

radius As

x

(8) From any external point, two equal tangents may be drawn to a circle. The line joining this point to the centre is an axis of symmetry

(8) From any external point, two equal tangents may be drawn to a circle. The line joining this point to the centre is an axis of symmetry

A

B

O T

(8) From any external point, two equal tangents may be drawn to a circle. The line joining this point to the centre is an axis of symmetry

arepoint external from tangents BTAT

A

B

O T

(8) From any external point, two equal tangents may be drawn to a circle. The line joining this point to the centre is an axis of symmetry

arepoint external from tangents BTAT

A

B

O T

BTAT :Prove

(8) From any external point, two equal tangents may be drawn to a circle. The line joining this point to the centre is an axis of symmetry

arepoint external from tangents BTAT

A

B

O T

BTAT :Prove

Proof: Join OA, OB and OT

(8) From any external point, two equal tangents may be drawn to a circle. The line joining this point to the centre is an axis of symmetry

arepoint external from tangents BTAT

A

B

O T

BTAT :Prove

Proof: Join OA, OB and OT

tangentradius 90 OBTOAT

(8) From any external point, two equal tangents may be drawn to a circle. The line joining this point to the centre is an axis of symmetry

arepoint external from tangents BTAT

A

B

O T

BTAT :Prove

Proof: Join OA, OB and OT

tangentradius 90 OBTOAT

OT is a common side

(8) From any external point, two equal tangents may be drawn to a circle. The line joining this point to the centre is an axis of symmetry

arepoint external from tangents BTAT

A

B

O T

BTAT :Prove

Proof: Join OA, OB and OT

tangentradius 90 OBTOAT

radii OBOA

OT is a common side

(8) From any external point, two equal tangents may be drawn to a circle. The line joining this point to the centre is an axis of symmetry

arepoint external from tangents BTAT

A

B

O T

BTAT :Prove

Proof: Join OA, OB and OT

tangentradius 90 OBTOAT

radii OBOA

OT is a common side

RHSOBTOAT

(8) From any external point, two equal tangents may be drawn to a circle. The line joining this point to the centre is an axis of symmetry

arepoint external from tangents BTAT

A

B

O T

BTAT :Prove

Proof: Join OA, OB and OT

tangentradius 90 OBTOAT

radii OBOA

OT is a common side

RHSOBTOAT matching sides in 'sAT BT

H

O T

collineargent common tan of

contact ofpoint and centres collinear is OTH

H

O T

collineargent common tan of

contact ofpoint and centres collinear is OTH

H

O T

Exercise 9E; 1aceg, 2bdfh, 3ac, 4bd, 6bc, 9, 10ac, 12b, 14, 16a


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