Across
1
Line touching circle at one point
5
Line segment connecting two circle points
6
Closed shape with straight sides
7
Total distance around a shape
12
Sum divided by count
Down
2
Value that does not change
3
Symbol representing unknown value
4
Corner point of a polygon
8
Line crossing from corner to corner
9
Exact correspondence on both sides
10
Steepness of a line
11
Part of a line with two endpoints