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| EF | = X = 0.235889894354

Semicircle = π Shaded / 2

Min ( | AD | ) = 7 / 2 = 3.5

Ratio of a / b = 1 / 2 = 0.5

Orange = 40 Square Units

Angle CTF = X = 45°

Quartercircle = 8.22479634591

Easy Way

Blue = 252 Square Units

Shaded Fraction = 9 / 11

Green / Blue = 1.8 = 9 / 5