Thanks. When used attributively, right hand is normally hyphenated: There's no sound coming out of the right-hand speaker. Chuck had a gun in his right hand.

Should left hand be hyphenated?

It's "left-hand side", the side nearest the left hand. "Left hand" forms a compound adjective and so should be hyphenated.

Is right hand corner hyphenated?

No. Either way, the reader arrives at the upper corner on the right-hand side. Upper andright apply to the word corner equally. So there is no need to hyphenate upper and right to force the reader to join them together.