a triangle has the sides lenghts of 6,8,9... is it acute obtuse right or equiangular

Question

maheshmeghwal9 · Answer

wow interesting:D
but i don't know how to do this:/

anonymous · Answer

haha i dont either

anonymous · Answer

the longer side will correspond to the larger angle.
so the largest angle of this angle is correspond to the longest side which length is 9
for any triangle, if three sides are a,b,c and three angles are A,B,C
we have
a^2 = b^2 + c^2 - 2·b·c·cosA 
cosA = (c^2 + b^2 - a^2） / （2·b·c) 
u can use the length of three side to work out the largest angle and judge wheather it is

anonymous · Answer

9^2=6^2+8^2-2*6*8*cosA
cosA=(9^2-6^2-8^2)/(2*6*8)=(-19)/96

anonymous · Answer

cosA is negative and A belongs to 0 to pi. so A is larger than 90 degrees.
so, it is a obtuse triangle

anonymous · Answer

where did you learn all this stuff??? and thanks for help me

anonymous · Answer

well, it is just formula. i learn it from books

anonymous · Answer

your really smart

anonymous · Answer

:)