Jawabanmu

2014-09-07T09:22:58+07:00
(5akar3)^2 = 5^2+5^2+2.5.5.cosO
75 = 25+25+50.cosO
75 = 50+50.cosO
50.cosO = 75-50
50.cosO = 25
cosO = 25/50
cosO = 1/2
O = 60  derajad
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