Yes, it is possible.
Yes, it is possible.
"Trisecting" is cutting into three equal parts, not four. Trisecting is impossible. Cutting into four equal parts is possible though, and trivial once you know how to bisect an angle.
Yes, it is possible.
The classical problem of angle trisection cannot be solved. If it were possible, it would provide the solution to a cubic equation. (-but it isn't and it won't!)
Doubling a cube Trisecting any angle
doubling the cube
doubling a cube and trisecting any angle
Doubling a cube and trisecting any angle
A. Trisecting any angle B. Doubling a cube
No, it isn't possible for a right triangle to have an obtuse angle.
No, it is not possible.
It can have a right angle, or more than one right angle, but it also is possible that it does not have any right angles.