Given quadrilateral PQRS in the diagram, find a line of reflection that will flip the figure onto itself.

Point P: (-3, 2)
Point Q: (3, -1)
Point R: (3, -4)
Point S: (-3, -7)

1 answer

To find a line of reflection that will flip the quadrilateral PQRS onto itself, we can look for symmetry in the points of the quadrilateral.

The points given are:

  • Point P: (-3, 2)
  • Point Q: (3, -1)
  • Point R: (3, -4)
  • Point S: (-3, -7)

We can find a line of reflection by determining the midpoints between pairs of points that are opposite each other. The vertices P and S, and Q and R appear to be opposite pairs.

Let’s compute the midpoints of the diagonal pairs:

  1. Midpoint of P and S: \[ \text{Midpoint M1} = \left(\frac{-3 + (-3)}{2}, \frac{2 + (-7)}{2}\right) = \left(-3, -\frac{5}{2}\right) \]

  2. Midpoint of Q and R: \[ \text{Midpoint M2} = \left(\frac{3 + 3}{2}, \frac{-1 + (-4)}{2}\right) = \left(3, -\frac{5}{2}\right) \]

We see that both midpoints share the same y-coordinate, \( -\frac{5}{2} \).

Now, let’s find the line of reflection that could be the vertical line that lies directly between the x-coordinates of P and S, and Q and R.

The x-coordinates of Point P and Point S are both -3, and the x-coordinates of Point Q and Point R are both 3. The reflection line is vertical and will be the average of -3 and 3:

\[ \text{Line of reflection} = \frac{-3 + 3}{2} = 0 \]

Thus, the equation of the line of reflection is: \[ x = 0 \]

This vertical line (the y-axis) reflects Points P and S, as well as Points Q and R, onto one another, flipping quadrilateral PQRS onto itself.

Final Answer: The line of reflection that flips quadrilateral PQRS onto itself is \( x = 0 \) (the y-axis).