AB = AC,则∠B = ∠C;
AD = AE,则∠ADE = ∠AED;
因此,∠BAD = ∠ADC - ∠B = ( ∠ADE + ∠EDC ) - ∠C
= ∠AED + ∠EDC - ∠C = ( ∠EDC + ∠C ) + ∠EDC - ∠C
= 2∠EDC = 30°
======================================================================================
数理方程没天理,常微分学常没分,实变函数学十遍,泛函分析心犯寒,随机过程随机过。微分拓扑躲不脱,微机原理闹危机,汇编语言不会编,机械制图机械制,量子力学量力学。
AD = AE,则∠ADE = ∠AED;
因此,∠BAD = ∠ADC - ∠B = ( ∠ADE + ∠EDC ) - ∠C
= ∠AED + ∠EDC - ∠C = ( ∠EDC + ∠C ) + ∠EDC - ∠C
= 2∠EDC = 30°
======================================================================================
数理方程没天理,常微分学常没分,实变函数学十遍,泛函分析心犯寒,随机过程随机过。微分拓扑躲不脱,微机原理闹危机,汇编语言不会编,机械制图机械制,量子力学量力学。


