As the exterior angles always add up to 360, you can find the number of sides by dividing 360 by the measure of your exterior angle, 30. This gives you 360/30=12, meaning your polygon has 12 sides.
If those are open circles shown on the number line the answer is D
A regular oval shape, traced by a point moving in a plane so that the sum of its distances from two other points (the foci) is constant, or resulting when a cone is cut by an oblique plane which does not intersect the base.
100 times it fits 100 times