Sin A=.... A.15/34 B.19/34 C.30/34 D.15/16 E.16/17

misalkan
b = A/2
A = 2b
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5² + 3² = 34
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jadi 
sin b = 3/√34
cos b = 5/√34

sin 2b = 2 . sin b. cos b
sin A = 2 . (3/√34) (5/√34) = 30/34