Across
1
Steepness of a line
4
Distance from center to edge of circle
5
Reference line in a graph
6
Divisible by two
7
Repeated addition
8
Number less than zero
9
Line segment connecting two circle points
Down
1
Exact correspondence on both sides
2
Lines that never intersect
3
Part of a line with two endpoints
10
Part of a circle's circumference
11
Closed shape with straight sides