Answer:
(1) Draw a line AB of length 1 unit.
(2) Draw another line BC of length 1 unit Perpendicular to AB.
(3) Now , join point A and point C forming a line AC.
Here , AC represents a line of length units
(4) Now , draw a perpendicular CD of length 1 unit at point c and join points A and D.
AD here represents length
(5) Similarly proceeding further we get Square root Spiral.