A:AnswerYou wouldn't need the Roku as this TV has those capabilities built in. You could add the Roku to one of the HDMI ports and use that instead, but if that's the case you wouldn't need a Smart TV.
A:AnswerI did not personally measure but specs are: Dimension
height 20.9 inches 20.9"(H) width 36.3 inches36.3" (W)
Samsung - 40" Class 5 Series LED Full HD Smart Tizen TV - Front_ZoomscreenSize 39.5 inchesscreenSize 39.5 inches 39.5"
heightWithStand 21.8 inches21.8" (H)
Product Height With Stand 21.8 inches
Product WidthInfo
36.3 inches
Product Depth With Stand
6.7 inches
Product Height Without Stand
20.9 inches
Product Depth Without Stand
2.9 inches
Product Weight With Stand
15.9 pounds
Product Weight Without Stand
15.4 pounds
Stand Width
36.3 inches