Question

已知a.b.c是三角形abc的三边,且满足a的平方+2b的平方+c的平方-2b（a+c）=0.则abc的形状?

Answer 1

是等边三角形.

a2 + b2 + b2 + c2 - 2ab - 2bc = 0

(a2 -2ab + b2) + (b2 - 2bc + c2) = 0

(a -b)2 +(b-c)2 =0

a=b b=c

a=b=c