In the figure below, arc SBT is one quarter of a circle with center R and radius 6. If the length plus the width of rectangle ABCR is 8, then the perimeter of the darkened region is

a) $\displaystyle 8+3pi$

b)$\displaystyle 10+3pi$

c)$\displaystyle 14+3pi$

d)$\displaystyle 1+6pi$

e)$\displaystyle 12+6pi$

Can you please show the steps? Thanks in advance

hey i forgot a major info. The graph stated that SR is 6, sorry i didn't include it on the graph!!