Can you calculate area of the Green shaded region | Three circles in a semicircle

The only number in this picture is 24. From it we find the radius of the three circles and the area of the green shaded region, step by step. CHAPTERS 0:00 The question 0:25 Drawing it again 0:43 The plan 1:02 The big radius 1:16 Three equal slices 2:00 Thirty degrees 2:54 How long is OP? 3:25 The small radius 4:18 The areas 4:50 The green area 5:06 Back to the picture