Find the direction cosines of the sides of the triangle whose vertices are `(3," "5," "" "4)` , `(" "1," "1," "2)` and `(" "5," "" "5," "" "2)` .

Explanation

direction ratios of side A B are` (-1-3),(1-5),` and `(2-(-4)) `i.e., `-4,-4,` and` 6` .



`sqrt{(-4)^{2}+(-4)^{2}+(6)^{2}} =sqrt{16+16+36} `

`
=sqrt{68} `

`
=2 sqrt{17}`



So the direction cosines of A B are



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