The height of an isosceles trapezoid is 6 and the bases are 4 and 20. Find the measures of the angles.

Isosceles Trapezoid

Longer side (a): 20

Shorter side (b): 4

Legs (c): 10

Diagonal (d): 13.416

Height (h): 6

Central median (m): 12

Circumcircle radius (rc): 11.18

Overlap (g): 8

Perimeter (p): 44

Area (A): 72

Acute angle (α): 36.87

Obtuse angle (β): 143.13