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Prebell
WB p. 195 # 1 – 2
Reflecting About the Origin
• Double reflection across 𝑥– and 𝑦–axes
• Find the opposites of both coordinates.
• (𝑥, 𝑦) → (−𝑥, −𝑦)
Get out your planner and composition book!
The vertices of a quadrilateral are 𝑌(0, 0),
𝐶(1, 3), 𝐹(5, 3) and 𝐺(4, 1). Find the
coordinates of its image after a reflection
about the origin.
The vertices of a triangle are 𝐸(−1, −2),
𝑉(0, 3), and 𝑋(3, 1). Draw the figure and its
image after a reflection about the origin.
What are the coordinates of the image?
Describe the transformation shown.
Describe the transformation shown.
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Translate the triangle 1 unit right and 5
units down. Then, reflect the image in
the 𝑦-axis.
Reflection Rules
• Reflect across 𝒙 − axis
(𝑥, 𝑦) → (𝑥, −𝑦)
• Reflect across 𝒚 − axis
(𝑥, 𝑦) → (−𝑥, 𝑦)
• Reflect about the origin
(𝑥, 𝑦) → (−𝑥, −𝑦)
• Reflect across 𝒚 = 𝒙
(𝑥, 𝑦) → (𝑦, 𝑥)
• Reflect across 𝒚 = −𝒙
(𝑥, 𝑦) → (−𝑦, −𝑥)
Reflect the figure across the line
𝑦 = 𝑥. Then, translate 5 units right
and 1 unit down.
Reflect the trapezoid in the 𝑥-axis.
Then translate the trapezoid 2 units
left and 3 units up.
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