If reflected over the x-axis, the quadrilateral would be in the fourth quadrant. N' would be at (1,-1) and P' at (6,-1). To reflect, look at the y-coordinate of the point and turn it to negative. With point Q, it's at (5,4) so we just flip the 4 to -4 and that's our point! (5,-4)
Basically you just need to multiply the two fractions together to get the depth of the turtle. Therefore the turtle is 3/12 miles deep or 1/4 mile deep.
