Question

几何题目（七年级 ）

Answer 1

∠BGD=∠BAG+∠ABG=1/2(∠BAC+∠ABC)

∠CGH=90°-∠GCH=90°-1/2∠ACB

∵∠BAC+∠ABC+∠ACB=180°

∴∠BAC+∠ABC=180°-∠ACB

∴1/2(∠BAC+∠ABC)=90°-1/2∠ACB

即∠BGD=∠CGH