北方野马
幼苗
共回答了21个问题采纳率:90.5% 举报
设∠ABC=X°
∠ABC=1/3(180°- ∠MNP)-10°
∠ABC=50°-1/3∠MNP
5/13(90°-∠ABC)=90°-∠MNP+10°
5/13(90°-50°+1/3∠MNP)=90°-∠MNP+10°
200/13°+5/39∠MNP +∠MNP =100°
44/39∠MNP=1100/13°
44∠MNP =3300°
∠MNP =75°
∠ABC=50°-1/3∠MNP=50°-25°=25°
1年前
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