Why isn t there a huge deep sea trench next to California like there is next to

Deep-sea trenches generally lie seaward of and parallel to adjacent island arcs or mountain ranges of the continental margins. They are closely associated with and found in subduction zones—that is, locations where a lithospheric plate bearing oceanic crust slides down into the upper mantle under the force of gravity.

Explanation:

"The result is a topographic depression where the oceanic plate comes in contact with the overriding plate, which may be either oceanic or continental. If the overriding plate is oceanic, an island arc develops. The trench forms an arc in plan view, and islands with explosive volcanoes develop on the overriding plate. If the overriding plate is continental, a marginal trench forms where the topographic depression appears to follow the outline of the continental margin. Explosive volcanoes are found there too"

cone

Step-by-step explanation:

If in the image you can see that the vertex with the angle of 90° is in the (0,0), then, looking at only the changes in the other vertex, we have.

Before the rotation, we have one vertex in the x = 0 line, and other vertex in the y = 0 line.

After the rotation, the vertex in the y = 0 line will draw a circle, while the point in x= 0 will not do anything (because the point is colinear to the axis of rotation).

Then our figure has a circular base and ends on a point, connecting those figures we can se that the figure is a cone.