As always, it's just about drawings.
The parametric equation of a circle has 3 variables and two equations. In 3-dimensional space, a circle is a spiral, but we only need one projection of this spiral into 2-dimensional space, and we also know how  the rest 2 it's projections on flat space look.
If we look at the equation of the sphere in parametric form, we will see that these are 3 equations and 5 variables:
x1 = sin(x4)*cos(x5); 
x2 = sin(x4)*sin(x5); 
x3 = cos(x4);
And so I wanted to see how the remaining 9 projections of the sphere onto 3-dimensional space look. It is very easy to do this with Maple.

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