Circumference, mowing, area calculation

Apskritimas
Given:
(enter only the data given in the task condition)
Radius of the circle OA:
cut string CD: ,
cut top EF:,
bevel angle COD: o
cutting angle AOB: o
-------------------------
Find:
Area of ​​the circle S
Length of the circle C
Area of ​​the segment AOB S1, length of the segment AB L
Area of ​​the segment CDF S2