4-18. In  textbook  fiqure  4-37,  the  compass spread O’P is equal to what distance? 4-19. 4-20. 4-21. 1. 2. 3. 4. In OP 1. 2. 3. 4. AB The radius OP minus AB The radius of arc EF minus AB The radius OP minus the radius of arc CD textbook  figure  4-38,  the  radius is equal to what distance? O’P The arc The arc The and What is line AB less the radius of CD line AB less the radius of EF sum of the radii of arcs CD EF the first step for constructing a compound curve, as shown  in  figure  4-40  of  the  textbook? 1. Draw  the  chords  connecting  AB, BC ,  CD, and DE 2. Erect a perpendicular bisector from A to B 3. Establish the random distance O₁A 4. Draw arc AB Assume that you just constructed the ogee curve skown in figure 4-42 of the textbook. Which of the following points was NOT established by geometric   construction? 1.   C 2.   D 3.   E 4.    O₁ 4-22. When using the pin-and-string method to construct an ellipse, which of the following  points  should  you  use  to determine the length of the string before drawing the perimeter of the ellipse? 1. Both end points of the minor axis and one focus point 2. Both end points of the major axis and  one  focus  point 3. Both foci points and one end point of the minor axis 4. Both foci points and one end point of the major axis Figure    4A IN  ANSWERING  QUESTIONS  4-23  AND  4-24,  REFER TO FIGURE 4A WHICH SHOWS THE CONSTRUCTION LINES USED FOR DRAWING AN ELLIPSE BY THE FOUR-CENTER  METHOD. 4-23. Line DE is equivalent to which of the  following  lines  or  distances? 1. Line DO 2. Line KO 3. Line AO minus line AK 4. Line AO minus line DO 4-24. Which  of  the  following  descriptions describes  point  K  correctly? 1. The end point of line KO, which is on the minor axis 2. The intersection of line AO with the  perpendicular  bisector  of line AE 3. The  intersection  of  line  KO  with the  perpendicular  bisector  of line AD 4. The end point of line KO, which is equal to the difference in lengths of lines AO and DO 24