Across
1
Corner point of a polygon
4
Divisible by two
6
Line segment connecting two circle points
7
Mathematical statement of equality
8
Number with digits after a point
9
Proven mathematical statement
11
Steepness of a line
Down
1
Symbol representing unknown value
2
Reference line in a graph
3
Rectangular array of numbers
5
The number representing nothing
10
Result of multiplication
12
Closed shape with straight sides
13
Lines that never intersect