Question

如图所示,BD是△ABC的中线,△ABD与△BDC的周长之差为3cm,AB的长为13cm,求BC的长

Answer 1

△ABD = AB + AD + BD

△BDC = CD + BC + BD 因为 BD为中线,AD = DC,因此 △BDC = AD + BC + BD

AB + AD + BD - (AD + BC + BD) = AB - BC = 3 or -3 且 AB = 13

因此,BC = 16 or 10