Angular diameter is the angle subtended by the diameter of the planet at the eye..
let the angular diameter be Ф.
Let the eye be at A, the center of the planet be O, and the diameter of the planet perpendicular to the line AO be BOC.
Ф = angular diameter = angle CAB = 2 * angle OAC
OB = OC = radius of the planet.
AO = 824.7 million km
tan (Ф/2) = OB / OA
Diameter of Jupiter = 2 * OB = 2 * 824.7 * 10⁶ * tan [ 35.72 / (2 * 60 * 60) ]⁰
= 142, 817.8 km