Question

In  triunghiul ABC,m(unghiului A)=90 grade,AB=12cm si cos B=0,6.Calculati perimetrul trunghiuluiABC!

Answer 1

ΔABC, A=90°, AB = 12, cosB = 0.6
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Pabc = ?
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BC = $\frac{AB}{cosB}$ = $\frac{12}{0.6}$ = 20
AC = $\sqrt{BC ^{2} -AB ^{2} }$ =$\sqrt{400 -144 }$ = 16
Pabc = AB + BC + AC = 12 + 20 + 16 = 48