The picture you posted seems to be seen from a 45° angle. This perspective is sometimes informally called "bird view". More formally, it is usually referred to as orthogonal, dimetric projection. Orthogonal means that all the world-axis are all parallel to a screen-axis (world-x is parallel to screen-x, world-y and world-z are parallel to screen-y). Dimetric means that two axis (y and z) are shortened by an equal amount, but the 3rd axis (x) isn't.
Dimetric projection does not use pespective shortening. That means objects far away from the viewer have the same size as those close to it. This makes the implementation of a 2d graphic engine much easier, because it needs no scaling.