Question

人教版七年级数学下册教材复习题七的第十题答案

要过程

Answer 1

10.(1) ∵∠2=1/2∠ABC,∠4=1/2∠ACB∴∠BGC=180°-∠2-∠4=180°-1/2（∠ABC+∠ACB)
（2）∠BCG=180°-1/2（∠ABC+∠ACB)
=180°-∠2-∠4
=180°-1/2∠ABC-1/2∠ACB
=180°-1/2(∠ABC+∠ACB)
=180°-1/2(180°-∠A)
=90°+1/2∠A

Answer 2

.(1) ∵∠2=1/2∠ABC,∠4=1/2∠ACB∴∠BGC=180°-∠2-∠4=180°-1/2（∠ABC+∠ACB)
（2）∠BCG=180°-1/2（∠ABC+∠ACB)
=180°-∠2-∠4
=180°-1/2∠ABC-1/2∠ACB
=180°-1/2(∠ABC+∠ACB)
=180°-1/2(180°-∠A)
=90°+1/2∠A