1. Why is three point control used in a resurvey? 

 a. The original corner was not found in the fourth direction.
 b. The fourth direction was never surveyed.
 c. Some controlling corners are lost.

2. In this diagram, how is the proportionate N-S location determined?

 a. One point control
 b. Two point control
 c. Single proportion
 d. Three point control

3. What about the E-W position?

 a. Single proportion
 b. Two point control
 c. One point control
 d. Three point control

4. Now, using the above diagram for record data and the diagram below for retracement, compute the proportionate lost corner location. 

Course 1
 a. N 0° 34' E 40.279 
 b. S 0° 25' W 40.356 
 c. N 0° 45' E 39.974

Course 2
 a. N 0° 14' E 40.372 
 b. S 0° 35' W 40.556 
 c. N 0° 24' E 39.878

Course 3
 a. N 89° 34‘ W 40.280 
 b. S 89° 44' W 42.526 
 c. N 89° 38' W 40.147

MOVE
 a. North 0.003 E 0.105
 b. North 0.006 E 0.120
 c. North 0.005 E 0.145

Correct Answers for Unit 2 Section 2B Review Exercise:

1. Why is three point control used in a resurvey?
Correct Answer: b. The fourth direction was never surveyed.

2. In this diagram, how is the proportionate N-S location determined?
Correct Answer: c. Single proportion 

What about the E-W position?
Correct Answer: c. One point control

3. Now, using the above diagram for record data and the diagram below for retracement, compute the proportionate lost corner location.

Course 1
Correct Answer: a. N 0° 34' E 40.279

Course 2
Correct Answer: b. S 0° 35' W 40.556 

Course 3
Correct Answer: c. N 89° 38' W 40.147

Move
Correct Answer: c. North 0.005 E 0.145