Question

证明题.1.如图8-7-96,已知∠1=∠2=∠3=55°,求∠4的度数.2.已知：如图8-7-91,∠1=∠2,∠C=

Answer 1

1.∠4=180-55=125°2.∵∠1=∠2∴∠1和∠2的对顶角,∠A1C=∠F2D ∵∠C=∠D∴∠A=180º-∠A1C-∠C=180º-∠F2D-∠D=∠F3.∵DE平分∠ADC ∴∠ADE=∠2=∠1∵∠ABC=∠ADC 而且BF和DE分别平分∠ABC和∠ADC∴∠ABF...