Squares and Triangles in a Circle

Square ABCD is inscribed in circle O with radius 30. Square EFGH is in a minor circular segment. E and F are on arc AB, while G and H are on cord AB. What is the length of EF?

Equilateral triangle ABC is inscribed in circle O with radius 30. Square EFGH is in a minor circular segment. E and F are on arc AB, while G and H are on cord AB. What is the length of EF?

Equilateral triangle ABC is inscribed in circle O with radius 30. Equilateral triangle EFG is in a minor circular segment. E and F are on arc AB, while G is on cord AB. EF//AB. What is the length of EF?