9-20. The dimensions for computations of area  by  resolution  are  obtained  in what manner? 1. By scale of the plot 2. By  field  measurements 3. Both 1 and 2 above 4. By  interpolation Figure  9A IN  ANSWERING  QUESTIONS  9-21  THROUGH  9-29, REFER TO THE FIELD NOTES SHOWN IN FIGURE 9A. THE ROAD IS 30 FEET WIDE WITH 2:1 FILL SLOPES. (IN THE NOTES, CUT IS PLUS AND FILL IS MINUS.) IN  ANSWERING  QUESTIONS  9-21  THROUGH  9-24, COMPUTE  THE  CROSS-SECTIONAL  AREA  AT STATION 2 + 00 BY USING THE FOLLOWING FORMULA: 9-21. What is the value of  d_r? 1. 17.4 ft 2. 24.8 ft 3. 27.2 ft 4. 29.0 ft 9-22. What is the value of  c? 1. -6.1  ft 2. -5.6 ft 3. -4.9 ft 4. -6.1 ft 9-23. What is the value of h₁? 1. 1.2 ft 2. 4.1 ft 3. 4.9 ft 4. 5.6 ft 9-24. What is the area of the cross section? 1. 166.8  ft 2. 228.1  ft 3. 373.7  ft 4. 475.6  ft IN  ANSWERING  QUESTIONS  9-25  THROUGH  9-28, USE  THE  COORDINATES  METHOD  TO  DETERMINE THE CROSS-SECTIONAL AREA AT STATION 3 + 00. THREE OF THE NEEDED COORDINATES ARE SHOWN IN THE NOTES; YOU WILL NEED THREE MORE COORDINATES. ONE OF THESE IS THE POINT OF ORIGIN THAT WILL BE AT CENTER-LINE  FINISHED  GRADE  (COORDINATES 0/0). THE  OTHER  TWO  COORDINATES  ARE  THE THREE ROAD EDGES TO THE LEFT AND TO THE RIGHT. 9-25. 9-26. 9-27. 9-28. What is the coordinate of the left edge of the road? 1. 0/15 2. 0/-15 3. 1.2/17.4 4. 7.0/29.0 When  you  write  down  the  coordinates beginning at the right edge of the road and go clockwise around the cross section, your first multiplication would be 1. -7[29 - 15] 2. -7[0 - 15] 3. -7[4.1 - 0] 4. -7[-17.4 - (-15)] Continuing  with  the  above  pro- cedure,  the  last  computation would  be 1. -4.1[29 - 14.4] 2. -4.1[-15 - 17.4] 3. -1.2[-15-0] 4. -1.2[-17.4  -  (-15)] What is the area of the cross section? 1. 67.3 sq ft 2. 85.3 sq ft 3. 156.6 sq ft 4. 313.2 sq ft 61