That's a classic problem that's been around for a very long time.
It's been proven that it's not possible to trisect any angle in general
with those tools, although there are a few specific angles, like a
right angle, for which it can be done.
No because a protractor would also be needed.
As a general rule, no.
No, and the proof was provided by Wantzel in 1837.
Yes and the trisections will form 4 angles of 22.5
First things first, the actual statement isn't "you can't trisect an angle" but rather "you can't trisect one with only a compass and straightedge." Some angles can be easily trisected--a 90-degree angle trisects into 30-degree segments-but to do it you need a protractor. Anyway, to check your work measure the angle you trisected and divide by three. If your trisections match, you got it right.
Yes! It is! I'm not perfectly sure how, but my father has, in fact, done this.
A compass and a straightedge