If the vertices of a triangle are $(2, -2)$,$(8, -2)$,and $(8, 6)$,what is the excenter opposite to the vertex $(2, -2)$?

In $\triangle ABC$,if $a : b : c = 4 : 5 : 6$,then the ratio of the circumradius to its inradius is

If $\triangle ABC$ is right-angled at $A$,then $r_2+r_3$ is equal to

In $\triangle ABC$,if $a=13 \text{ cm}, b=14 \text{ cm}$ and $c=15 \text{ cm}$,then its circumradius $R$ is:

If the sides of the triangle are $5K, 6K, 5K$ and the radius of the incircle is $6$,then the value of $K$ is equal to

$AD, BE$ and $CF$ are the perpendiculars from the vertices of a $\Delta ABC$ to the opposite sides. The ratio of the perimeter of $\Delta DEF$ to the perimeter of $\Delta ABC$ is: (where $r$ is the inradius and $R$ is the circumradius of $\Delta ABC$)