To find the vertices of square A′B′C′D′ after reflecting square ABCD first across the x-axis and then across the y-axis, we follow these steps:
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Identify the original vertices of square ABCD. Let's assume that the vertices are:
- A(x1, y1)
- B(x2, y2)
- C(x3, y3)
- D(x4, y4)
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Reflect across the x-axis. The reflection rule across the x-axis is to change the sign of the y-coordinate:
- A’(x1, -y1)
- B’(x2, -y2)
- C’(x3, -y3)
- D’(x4, -y4)
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Reflect across the y-axis. The reflection rule across the y-axis is to change the sign of the x-coordinate:
- A’’(-x1, -y1)
- B’’(-x2, -y2)
- C’’(-x3, -y3)
- D’’(-x4, -y4)
Now substituting the coordinates from square ABCD into the above steps (assuming for example, A(3, 4), B(7, 4), C(7, 8), D(3, 8) as original vertices):
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Reflect across the x-axis:
- A’(3, -4)
- B’(7, -4)
- C’(7, -8)
- D’(3, -8)
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Reflect across the y-axis:
- A’’(-3, -4)
- B’’(-7, -4)
- C’’(-7, -8)
- D’’(-3, -8)
This gives us the vertices of square A′B′C′D′:
- A′(-3, -4)
- B′(-7, -4)
- C′(-7, -8)
- D′(-3, -8)
Therefore, the correct answer is: Square A′B′C′D′ has vertices A′(−3,−4) , B′(−7,−4) , C′(−7,−8) , and D′(−3,−8).