To find the vertical line of symmetry for the given quadrilateral, we need to determine which x-coordinate would create a mirror effect that reflects the shape onto itself.
The vertices of the quadrilateral are:
- (0, 0)
- (−8, 0)
- (0, −6)
- (−8, −6)
The quadrilateral is symmetric around the vertical line that lies midway between the leftmost and rightmost points.
The leftmost point is at \( x = -8 \) and the rightmost point is at \( x = 0 \). The midpoint (which acts as the line of symmetry) can be calculated as follows:
\[ \text{Midpoint} = \frac{-8 + 0}{2} = \frac{-8}{2} = -4. \]
Thus, the equation of the vertical line of symmetry is:
\[ x = -4. \]
So, the complete answer is:
\( x = -4 \) is the vertical line of symmetry of the quadrilateral.