Across
3   The area of the triangle formed by
3 collinear points is ? (4) 
4   These lines have equal slopes. (8) 
6   The axes meet at this point. (6) 
8   The axes divide the plane into
four distinct regions called ? (9) 

Down
1   Tan of angle which the line makes
with the positive direction of the
xaxis. (5) 
2   A number that identifies a
position relative to an axis. (10) 
5   The reference lines of the
coordinate plane. (4) 
7   A two dimensional flat surface. (5) 
