>
数学
>
如图△ABC中,AD⊥BC,BE⊥AC,BF=AC,如果∠EBC=25°,则∠ACF=______.
人气:406 ℃ 时间:2020-01-29 23:11:18
解答
∵AD⊥BC,BE⊥AC,∴∠ADC=∠BDF=∠BEA=90°,∴∠FBD+∠BFD=90°,∠DAC+∠AFE=90°,∵∠AFE=∠BFD,∴∠FBD=∠DAC=25°,在△BDF和△ADC中,∵∠BDF=∠ADC∠DBF=∠DACBF=AC,∴△BDF≌△ADC(AAS),∴DF=DC...
推荐
如图,在△ABC中,AD⊥BC,BE⊥AC,垂足分别为D、E,AD与BE相交于点F,若BF=AC,求∠ABC的大小.
如图,在△ABC中,∠C=90°,∠ABD=2∠EBC,AD∥BC, 求证:DE=2AB.
如图2,以三角形ABC的边AB,AC为边在三角形ABC的外部分别作等边三角形ABE和等边三角形ACF,CE与BF相交O
如图:点E是三角形ABC的边AC上的一点,且AE=2EC,BE=8,AD垂直BC于D,TAN角EBC=1/4,求AD的长是多少
如图,△ABE和△ACF分别是以△ABC的AB,AC为边的等边三角形,CE,BF相交于点O(1)求证:∠AEC=∠ABF.(2)求∠BOE的度数.急.
已知O为三角形ABC内一点,∠AOB=150°,∠BOC=90°,若OA=a,OB=b,OC=c,且|a|=2,|b|=1,|c|=3, (1)用a,b表示c (2)求a•(b-c)
刻舟求剑的故事中明白了什么道理
怎样阅读写人类文章
猜你喜欢
football,in,every,we,piayground,piay,morning,the(连词成句)
沸点差别与分馏能否的关系
______ you don't konw the meaning of a new word,you can look it up in a dictionary.
do you have knives?yes----we have five.
助动词只能在一般现在时的疑问句式用到吗,比方DO
Tom got very angry when he realized he__ A.was being made fun of B.is made fun of C.had made fun of 谢啦!
用英语怎么翻译“太年轻太天真”
when the man saw the car accident on the highway,he stopped______offer help
© 2024 79432.Com All Rights Reserved.
电脑版
|
手机版