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given a regular octagon in a circle of radius 18 cm. find the area of the octagon!
##Quiz #116 ##
Jawab:
Penjelasan dengan langkah-langkah:
soal
r= 18 cm
α = 360/8 = 45
luas segi 8 = 8 . 1/2. 18. 18. sin 45
= 648√2 cm²