# Ideas in Geometry/Instructive examples/Problem

In city geometry and Euclidean Geometry, a parabola is a set of points such that each of those points is the same distance from a given point, A, as it is from a given line, L. This is a little trickier in city geometry because there are no curved lines.

Question 22 asks you to draw a parabola determined by the point (2,0) and the line y=0. So in this case A from the definition is (2,0) and L is y=0.

The first thing you should do is draw on a coordinate plane the point (2,0) and the line y=0. (Hint: y=0 is a horizontal line that exists along the x-axis) You should notice is that the point (2,0) is on the line y=0. Since the point lies on the line, there is only one point where the point of a parabola can be the same distance from the point (2,0) and the line y=0 and that point is (2,0) because (2,0) is zero distance away from the point (2,0) and the line y=0. This means that the parabola created in this problem is actually just one point: (2,0). The picture looks like this: