Question

求答案，T^T

Answer 1

设∠A=x°
∵∠A=1/2∠C=1/2∠ABC
∴∠C=∠ABC=2∠A=2x°
∵∠A+∠ABC+∠C=180°
∴则有方程：
x+2x+2x=180
x=36
即∠A=36°
∵∠A=1/2∠C=1/2∠ABC
∴∠C=∠ABC=72°
∵BD平分∠ABC
∴∠ABD=∠CBD=1/2∠ABC=36°
∵∠BDC=∠A+∠ABD
∴∠BDC=72°
即∠A=36°，∠BDC=72°