The only way we could get a line of symmetry through this figure is to use a vertical line. The only way to get symmetry would be to put the vertical line though the point x = 3. When we do that, we can see that the end points of the base are both one unit away from the line of symmetry. The end points I'm talking about are the points at the coordinates (2, 4), and (4, 4)
Cutting her time by 50% means reducing her time by half. Half of 45 seconds is 22.5 seconds. Therefore, to make the team, she must run a lap in 22.5 seconds.