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2014-04-28T16:02:22+03:00
Cos B=AC/BC=2/3
AC/12=2/3⇒AC=2.12/3=8 cm
cu Pitagora AB²=BC²-AC²
AB²=144-64=
AB²=80
AB=4√5
A=catetaxcateta/2=8x4√5/2=16√5 cm²
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