There is a rectangle on a grid with the corners coordinates being A(8,5) R(8,-1), D(-2,-1), W(-2,-5)

Examine the polygon in the figure shown. Identify a line of symmetry that will flip the figure onto itself.
A. x-axis
B. x=3
C. y-axis
D. y=3

1 answer

To determine if there is a line of symmetry for the rectangle formed by the points A(8,5), R(8,-1), D(-2,-1), and W(-2,-5), let's first analyze the coordinates of the rectangle.

  1. The points A(8,5) and R(8,-1) are vertically aligned (same x-coordinate).
  2. The points D(-2,-1) and W(-2,-5) are also vertically aligned.
  3. The rectangle can be confirmed since opposite sides are parallel and equal in length.

To find a line of symmetry, we need to see if the rectangle can be folded over a line and result in both sides matching perfectly.

  • x-axis: This line would reflect points A and R (top edge) to below the x-axis, and D and W (bottom edge) to above the x-axis, which does not maintain symmetry. So not a line of symmetry.

  • x = 3: This line is positioned between the left and right edges of the rectangle (from x = -2 to x = 8). Reflecting points across x = 3 would not put them in their original positions since the distances from that line are unequal. So not a line of symmetry.

  • y-axis: The points at A and R would reflect to (8,5) and (8,-1) on the opposite side of the y-axis, and D and W would change to (-2,-1) and (-2,-5) which do not match their original locations. So not a line of symmetry.

  • y = 3: This line runs through the midpoint of the vertical height of the rectangle. The top edge (points A, R) would reflect down to points D and W respectively. Since the rectangle maintains a consistent distance from this line on both sides, it creates a perfect match.

Thus, the line of symmetry identified is:

D. y = 3