In a $\Delta$ if the angles are in the ratio $3: 2: 1$, then the ratio of its sides is

In a $\triangle A B C$, if $B C=5, C A=6$ and $A B=7$, then the length of the median drawn from $B$ onto $A C$ is

In $\triangle A B C$, if $A B: B C: C A=6: 4: 5$, then $R: r$ is equal to

If $(\alpha, \beta)$ is the orthocentre of the triangle with the vertices $(2,2),(5,1),(4,4)$, then $\alpha+\beta=$