Across
1
Part of a line with two endpoints
3
Line segment connecting two circle points
5
Reference line in a graph
7
Line crossing from corner to corner
9
Number with digits after a point
10
Proven mathematical statement
12
Number divisible only by 1 and itself
Down
1
Result of addition
2
Mathematical statement of equality
4
Split into equal parts
6
Part of a whole number
8
Closed shape with straight sides
11
Steepness of a line
13
Symbol representing unknown value