Correct Answer: 90 D in RA means 90 Degrees in Right Angle It is a logic question which is to be eloborated Some more of its kind are: 1 52 W in a Y - 52 Weeks in a Year 2 7 C in a R - 7 Colours in a Rainbow 3 9 P in SS 4 5 C in an OF 5 12 S of the Z
