>>13947355Horizontal axis is stretched to r * cos(theta) by the angle.
Vertical Axis is not stretched by the tilt, stays as r
Area of an ellipse is pi * a * b, where a and b are the radii in either direction.
So the area of that projection is pi * r * r * cos(theta)
pi r^2 is A for an untilted circle
So the area is A cos(theta)
