Jawabanmu

2014-02-26T16:33:20+07:00
GC = α
AC = α \sqrt{2}
CP =  \frac{1}{2} AC =  \frac{1}{2} α \sqrt{2}
GP =  \sqrt{GC^{2} + CP^{2}  }
      =  \sqrt{ \alpha^{2} +  (\frac{1}{2} \alpha \sqrt2} )^{2}  }
      =  \sqrt{ \alpha^{2} +  \frac{1}{2}\alpha^{2} }
      =  \sqrt{ \frac{4\alpha^{2} + 2\alpha^{2} }{4}}
      =  \sqrt{ \frac{1}{4} . 6 .   \alpha^{2} }
      =  \frac{1}{2} \alpha\sqrt{6}