1. (0,4) (4,0) (2,0) (4,2) y = -2 + x y = 4 - x

2. A B C

3. A 1 0A0A0 0101A1A1 A0A0 0 A1A1 0101

4. A BC 1 1 2 4 3 6 5 8 7 0 0

5. Lines cross Lines don’t cross

6. n 1 =8 n 2 =6

7. (x1,y1)(x1,y1) (x2,y2)(x2,y2) (x3,y3)(x3,y3) (x4,y4)(x4,y4) (x5,y5)(x5,y5) x2-x1x2-x1 (y 1 +y 2 )/2

8. A B C D 874 95 199 767 - + 0 0 AREAAREA A B

9. 0001 0203 1 23

10. 0001 02 1 23 032 030 033 A A B 0312 A 0311 B 0313 A 0310 A

11. park ParkNULL River2 Village20 Well1113 well village

12. 1 2 3 4 5 6 14 7 8 910 11 12 13 Map (1) A C (2,3) D (4,5) B (14) E (6,7,8)F G (9,10) H (11,12,13)