已知三个角1,2,3满足:1与2互补,2与3互余,试求1-3的大小!

问题描述:

已知三个角1,2,3满足:1与2互补,2与3互余,试求1-3的大小!
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1+2=180
2+3=90
1+2-(2+3)=1-3=180-90 =90