Question

三角形ABC中若角C+角A=2角B角C-角A=180度则角A=()角B=()角C=()

Answer 1

已知 C + A =2B.1

C - A =80.2

由三角形内角和定理知A +B +C =180.3

1+2得2C = 2B + 80

即 C = B + 40.4

1-2得2A = 2B - 80

即 A = B - 40.5

将4、5 带进3中得B - 40 + B + B + 40 = 180

所以B = 60.6

将6 带入4和5分别求出C = 100 A = 20