When you translate something in geometry, you're simply moving it around. You don't distort it in any way. If you translate a segment, it remains a segment, and its length doesn't change. Similarly, if you translate an angle, the measure of the angle doesn't change.
The number pi is a constant, it's the ratio of a circles circumference to it's diameter.
Yes, 13 is the remainder.
See dat pic for full solution.