Cambridge International Mathematics

Example 4 Self Tutor

x=80and y= 120 fexterior angles of a cyclic quadrilateralg

EXERCISE 27B.1

1 Findxgiving reasons:

abc

de f

2 Find the values of the unknowns in the following:

abc

de f

Find and , giving

reasons for your answers:

xy

120°

x°

80°

y°

A

B

C

D

x°

y°

80°

70°

R Q P

S T

x°

100°

A

B

C

D

130°

y°

O

x°

K

L

M

N

()x¡+¡20°

x°

A B

C

D

x°

73°

A B

C

D

x°

2°x

AB

D C

x° ()2 -70x °

P

Q

R

S T

81°

x°

A

B C

D E

x°

()180¡-¡x°

A

B

C

3°x y° O x° D

558 Circle geometry (Chapter 27)

x° 110°

O

75°

x°

y°

IGCSE01

cyan magenta yellow black

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100 100
(^05255075950525507595)
100 100
Y:\HAESE\IGCSE01\IG01_27\558IGCSE01_27.CDR Wednesday, 12 November 2008 9:09:49 AM PETER