Page 71 - Math Course 2 (Book 2)
P. 71
Transformations in Geometry
Dilation in a Coordinate Plane
Example
A polygon has vertices A(–1, 1), B(1, 1), and
C(1, 2). Graph the polygon and the image of the Answer
polygon after a dilation centered at the origin with
a scale factor of 3. y
C’
To dilate the polygon, multiply the coordinates of
each vertex by 3
To dilate the polygon, multiply the coordinates of
each vertex by 3. A’ B’
A (–1, 1) ® A' (–3, 3) C
A B
B (1, 1) ® B’ (3, 3) O x
C (1, 2) ® C’ (3, 6)
Your Turn!
Reflections in a Coordinate Plane
The vertices of a figure are Q(–2, 4), R(–3, 1), S(3, –2), and T(4, 3). Graph the figure and the image of the
figure after a reflection over the y-axis.
A. C.
Answer
B. D.
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