A certain trapezoid happens to be a bicentric quadrilateral. The trapezoid's circumradius is twice the inradius. What are the measures of the angles of the trapezoid?

If the circumradius is five times the inradius, then what are the measures of the angles?

What is the ratio of the circumradius and inradius when the longer base of the trapezoid is a diameter of the circumcircle?