Tolong dijawab ya pliss
AC / sin B = BC / sin A
20 / sin 45 = BC / sin 60
20 / 1/2 akar 2 = BC / 1/2 akar 3
20 / akar 2 = BC / akar 3
kalikan silang,
akar 2 BC = 20 akar 3
BC = 20 akar 3 / akar 2
BC = 20 akar 3 x akar 2 / 2
BC = 10 akar 6 cm
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