Page 375 - Math Smart - 7

y
1 k

R n R • R' RL
CO j u
J T n J'
\ \ 0 p
\
\ V
S ■V Y
J
->-.V
-
5 4 - 3 _2 -1 u 2 3 4 i _5 -4 -2 2 3 4 S
The reflected triangle R'ST is a mirror image of triangle RSI. It has the same size
and shape as the original triangle. The two triangles are congruent.

Example 2

0 Draw and label AABC on a coordinate grid. Use these coordinates: A (-4, 5), B

(-5, 1)andC(-2, 2).
0 Reflect AABC along the y-axis.
0 Label and state the coordinates of the reflected image (AA'B'C). To reflect in the y-axis
means to use the y-axis
Solution
as the mirror line.
0 Plot the points on the grid. Label the points A, B and C Join the points with In this example, the line
straight lines. of reflection is the y-axis.

^ •A
The distance between
c point A and the y-axis
should be the same as the
B
distance between point B
_7 _6 -5 ^ -3 -2 -1 0 1 2 3 4 5 6 7 and the y-axis.

0 Each point of AABC is reflected along the y-axis.

ygl C

sf e( tior
>■ X
7 - 5 - 5 --4 - 5 ' _ 0 } 4 .> 6 /

0 AABC is the object that is reflected.
AA'B'C is the image formed as a result of the reflection.
The coordinates of the translated image are: A' (4, 5), B' (5, 1), C (2, 2)