三角形ABC中,角A角B.角C的对边分别为a.b..c,已知关于X的方程X平方－（c+4）X+4c+8==0

三角形ABC中,角A角B.角C的对边分别为a.b..c,已知关于X的方程X平方－（c+4）X+4c+8==0
三角形ABC中,角A角B.角C的对边分别为a.b..c,已知关于X的方程X平方－（c+4）X+4c+8==0

三角形ABC中,角A角B.角C的对边分别为a.b..c,已知关于X的方程X平方－（c+4）X+4c+8==0
1)因为a,b是关于x的方程的两根
所以a+b=c+4,ab=4c+8
所以a^2+b^2=(a+b)^2-2ab=c^2
由余弦定理知cosC=(a^2+b^2-c^2)/(2ab)
将a^2+b^2=c^2代入可得cosC=0
所以角C=90度

题目没有完善，漏了点什么吧

题目不完整，一般这类题目，你可以根据方程有解的条件和三角形的一些隐性条件来求解，最好把题目补充完整了，大家才好帮你

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The Ugg Boot or only Uggs namely some sort of generic term as just a manner of sheepskin shoe that's been produced with Australia and New Zealand for virtually 200 years. Originally the were creature ...

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The Ugg Boot or only Uggs namely some sort of generic term as just a manner of sheepskin shoe that's been produced with Australia and New Zealand for virtually 200 years. Originally the were creature cried "Ug alternatively possibly Ugh Boots" that's short for "Ugly". However one Us Importer (Koolaburra) presented taking that reach namely the appoint Ugg derives from the path which the shoe "embraces" this wearer's foot in addition to thighs. However on account of trademark issues,UGG 2011, Uggs are at and large understood in this retail earth purely for Sheepskin Shoes. Originally in Quotes and New Zealand namely cozy and lukewarm footwear was being worn at social teams like Bogans,Ugg Discount, westies and Bevans in public places. However, maximum additional Australians could only wear them near to your house or at at present the maximum equitable on the road to the local mart. The boots indeed became popular over the 1960's with people and competitive swimmers since they kept them warm whilst appearance the water. It is thought numerous fashionable Australian actors/actresses have probably being wearing Ugg shoes in private long,Classic Mini, it was at the peak of Pamela Anderson began wearing manboobs that she received earned in Australia to assist keep her thighs comfy during breaks in filming the warmhearted accepted TV show Baywatch,ugg bailey triplet, it's thought human in north america started to take amuse in it in these shoes.However,Ugg Online, since 2003 the boot has grown to be very popular in USA with the marketing of the merchandise at an Us Company cried Ugg .

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