在三角形ABC中，三边a，b，c成等差数列，sinA，sinB，sinC成等比数列，试判断三角形ABC形状。

在△ABC中，若三边a，b，c成等差数列，sinA，sinB，sinC成等比数列，则△ABC的形状是______三角形．（填~

∵三边a，b，c成等差数列，∴a+c=2b①，又sinA，sinB，sinC成等比数列，∴sin2B=sinA?sinC，根据正弦定理化简得：b2=ac②，由①得：b=a+c2，代入②得：(a+c)24=ac，即（a-c）2=0，∴a=c，故b=a=c，则三角形为等边三角形．故答案为：等边

等边三角形

a/sinA =b/sinB =c/sinC,且sinA，sinB，sinC成等比数列，
所以b^2=ac. 又a+c=2b。
上面右边平方减去左边4倍。得（a-c)^2=0
so:a=b=c.等边三角形。

a,b,c成等差数列，则sinA,sinB,sinC也成等差数列
sinA,sinB,sinC也成等比数列，那么只能是sinA=sinB=sinC
也就是a=b=c
所以ABC是等边三角形

2b=a+c,b^2=a*c,联立求解。发现（a-c）^2=0 所以a=c , 又因为2b=a+c=2a，所以是等边吧

Happy whole family (front row center for the beam-Star)

15 years ago, they picked up a helpless disabled elderly Dangdie, neighbors are all thumbs.
Ji recent years, it was found that they picked up the father suddenly become \Suddenly, praised gradually become supercilious. The face of all this,uggs australia, how should they do?
\.
\
\
\
\
whatever reason, had prompted his father to drive Xiao-Ping? This had to from 15 years ago.
\Suddenly, the door knock on the door sounded.
son, Wang Jun opened the door, the two strangers standing in front of the drenched, precisely, is a person carrying another person with a back pocket, back pockets of people still do not live groan.
\
Jia-Qiang Wang looked for a long time, only to find the back pocket of the man is 3 months rent to live in their own homes before the tenant beam star, half months ago, only to leave from here.
original, Liang star broke his leg, no money, was not any place to go, before returning here.
\
Boy in the husband's opposition and his son, Jia-Qiang Wang's wife had spent the whole night Xiao-Ping Liang star sent to a nearby hospital.
beam star is Kuanba retired workers, small big tongue, often drooling and also received injuries, the right hand mobility. He was married once, but a man without children, without parents after a divorce in 1995, without relying on, then rented a small hut of the Jia-Qiang Wang, less than 3 months will go ... ...
pelvis dislocation
beam star, spent a week in hospital before discharge. Meanwhile, Xiao-ping had boiled bone soup every day he sent for him, can not be paid that portion of medical expenses reimbursed.
had Xiao-ping was not working, the family 300 yuan per month thanks to Jia-Qiang Wang wages. \
\
15 years, he Dangdie honor

Since then, the task falls Zhao Gu Liangming star Xiao-ping who have been - to him do the laundry, separate meals, fed-side water, and he even received feces draining, but also Wang Jun told him Grandpa.
time goes by, under the influence at once Xiao-ping, Jia-Qiang Wang and his son also received this from the bottom of my heart for the elderly. No toilet at home, father and son back every week to the beam from a kilometer away star bath shower, Cuobei.
\
Two years later, Leung stars can finally own a cane to walk up.
\
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Thus,herve leger dress, Xiao-ping and the husband had confessed the father Boy, every meal, I always let him sit.
At this point, Kuanba know that Jia-Qiang Wang The couple broke a \crazy, picking up a tired old man so. \Zeng Xiao-ping is always trying to communicate with him and let him relax a bit. Last year, 70 birthday star Liang, Ji Wang also specially organized tables, please visit the bustling neighborhood after his birthday.
\One day in 2000, Liang star who suddenly took out a book: \

had Xiao-ping, a star that beams a pension, but they know very little, never thought of his money.
this Ji, enterprise retirees with rising wages, and now, the monthly retirement income star beam has reached 1409.2 yuan.
\Liang star said.
had Xiao-ping in the shantytowns where a monthly pension of 1,000 yuan can be considered a lot of money, and this poor old man was bored turning into \Jia-Qiang Wang, a person's face, gradually become disliked by the appreciation.
\;

but the more people understand them, \said.
hear the gossip of others, has repeatedly let Dr Xiao-Ping star was renting an apartment, give him his daily meal delivery, Zhao Gu his living,uggs boots outlet, but he is not, do not go to nursing home.
yesterday, see the \do not understand his words, he worried, and pointed to Jia-Qiang Wang family, and then sit there straight hard to lose control of their fingers, made a Shudamuzhi gesture. See all understand what he meant, he was quiet.
\.
chief reporter Zhou Liwen

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