Challenge
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274 Coordinate geometry (Chapter 12)
1 Triangle ABC sits on thex-axis so that vertices A and
B are equidistant from O.
a Find the length of AC.
b Find the length of BC.
c If AC=BC, deduce that ab=0.
d Copy and complete the following statement based
on the result ofc.
“The perpendicular bisector of the base of an
isosceles triangle ......”
2 OABC is a parallelogram. You may assume that the
opposite sides of the parallelogram are equal in length.
a Find the coordinates of B.
b Find the midpoints of AC and OB.
c What property of parallelograms has been deduced
inb?
3 By considering the figure alongside:
a Find the equations of the perpendicular bisectors
of OA and AB (these are the lines PS and SQ
respectively).
b Useato find thex-coordinate of S.
c Show that RS is perpendicular to OB.
d Copy and complete:
“The perpendicular bisectors of the sides of a
triangle ......”
x
y
B,()a¡0
C,()bc¡
A,()-¡0a O
x
y C,()bc¡ B
O A,()a¡0
A,()2¡2ac
R,()b¡0 B,()2¡0b
x
y
P Q
S
O
IGCSE01
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(^05255075950525507595)
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y:\HAESE\IGCSE01\IG01_12\274IGCSE01_12.CDR Thursday, 23 October 2008 12:04:10 PM PETER