Across
1
Number divisible only by 1 and itself
4
Number that divides evenly into another
6
Reference line in a graph
7
Longest side of a right triangle
12
Steepness of a line
13
Divisible by two
Down
2
Distance from center to edge of circle
3
Math using letters for unknown values
5
Proven mathematical statement
8
The number representing nothing
9
Repeated addition
10
Part of a circle's circumference
11
Line segment connecting two circle points