Cambridge International Mathematics

682 ANSWERS

EXERCISE 4E

1ax= 120 bx=95 c x=60

2a 108 o b 135 o c 144 o d 162 o e 176 : 4 o

f

¡

180 ¡^360 n

¢o

3a 8 sides b 24 sides c 180 sides d 720 sides

4a 6 sides b 12 sides c 72 sides d 360 sides

Review set 9B

1a...... are equal in size.

b...... are supplementary (add to 180 o).

2ax=72fcorr. anglesg b x=20fangles on a lineg

c x= 242 fangles at a pointg

dx=65fangles on a line/alternate anglesg

ex=40fvertically opposite/co-interior anglesg

3 yes fangles on a line/alternate angles equalg

4ax=62 bx= 152 c x=68

5 ¢ABC is isosceles since AbCB=AbBC=62o

fangles on a line/angles in a triangle/isosceles triangle theoremg

6ax= 122 fangles in a quadrilateralg

bx=60fopposite angles of parallelogramg

y=5 fopposite sides of parallelogramg

c Must be a parallelogram and so a rectangle.

fequal opposite sides and one angle a right angleg

x=35, y=55 falternate anglesg

7ax= 110 fangles in a pentagong

bx= 120 fangles in a hexagong

c x= 100 fexterior angles of a polygong

dx=75fexterior angles of a polygong

Review set 10A

1aa=73fangles on a lineg

bb=90fangles on a lineg c c=56fvert. opp. anglesg

da= 110falternate anglesg, b= 110fvert. opp. anglesg

ex=40fangles on a lineg

2ax=60fangles in a¢g b a= 131fext. angle of a¢g

c x=2fequal sides of equilateral triangleg

3 x=96fcorr. angles/isosceles¢theorem/angles in a¢g,

y=96fcorr. anglesg

4aright angled scalene bobtuse angled scalene

c obtuse angled isosceles

5ax=56fangles on a line/angles in a quadrilateralg

ba=44fangles in a triangleg, b=46falternate anglesg,

c=88fisosceles triangle theorem/angles in a triangleg

6 Polygon Number of sides Sum of interior angles

pentagon 5 540 o

hexagon 6 720 o

octagon 8 1080 o

7a 150 o b 160 o

8ax= 100 fvert. opp. angles/angles of a regular polygong

bx= 140 fangles of a regular polygong

CHALLENGE

1asum= 180o

bSum always seems to be 180 o(or close to it).

c The sum of the angles of all ‘ 5 -point stars’ is 180 o.

dHint: BbEI+EbBI=JbID

eThe angle sum of all ‘ 7 -point stars’ is 540 o.

EXERCISE 5A

1a Subjects taught by teachers in a school

b 33 :3%

2aAston 195 o,

Bentley 90 o,

Corvette 75 o

b

3a Midday temperature in Kingston

b Rainfall in Kingston

4aStem Leaf

2 974175

3 305464

4 6028

5 8710

b Stem Leaf

2 145779

3 034456

4 0268

5 0178

Key: 5 j 8 means 58

5a Science Test results

29

389

4 347

5 135666899

6 1223444677889

7 01234568

8 0001788999

9 0225 Key: 2 j 9 means 29

b28%

c 12%

6a 188 students b 9 : 5 o c 1440 students

7aThe data is continuous. Therefore we use a line graph.

b Shadow length over time data

0

2

4

6

8

Maths English Science

Humanities

Mod. Languages

Theatr. Arts

PE

frequency

subject

Bentley

Aston

Corvette

18

20

22

24

26

Su Mo Tu We Th Fr Sa

temp (°C)

day

024681012

Su

Mo

Tu

We

Th

Fr

Sa rainfall (mm)

day

0

10

20

30

40

0800 1000 1200 1400 1600

shadow length (m) time

Toy car makes

IB MYP_3 ANS

cyan magenta yellow black

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100 100
(^05255075950525507595)
100 100
Y:\HAESE\IGCSE01\IG01_an\682IB_IGC1_an.CDR Tuesday, 18 November 2008 2:36:18 PM PETER