8.40 Chapter 8
reflection ˀ࢛ axis of reflection ˀ࢛ൿ
(a) Coordinates of Al = (5 , -1 + 4) = (,)53
Coordinates of Bl = (5 , -4 + 4) = (,)50
Coordinates of Cl = (2 , -1 + 4) = (,)23
(b)
A
B
C
1
1
0 2 3 4 5 6
-1
-2
-3
-4
2
3
4 y
x
A'
B'
C'
Solution
The figure shows 3PQR with vertices
P(-3 , 4), Q(-1 , 1) and R(-2 , 1). P, Q
and R are translated to the right by 3 units
to Pl, Ql and Rl respectively.
(a) Find the coordinates of Pl, Ql and Rl.
(b) Draw 3PlQlRl in the figure.
14
Instant Drill
QR
P
1
1
0 2 3
-3 -2 -1
2
3
4 y
x
➥ Ex 8D 13
B Reflection
In the figure, we flip a point P along the straight line l to the other side
and obtain a new point Pl.
m
P
m
m
P P'
This kind of transformation is called reflection of a point and the straight
line l is called the axis of reflection.
Pl(0 , 4), Ql(2 , 1), Rl(1 , 1)
Q'R'
P'