Across
1
Number that divides evenly into another
3
Closed shape with straight sides
4
Proven mathematical statement
5
Round shape with all points equidistant
6
Divisible by two
9
Longest side of a right triangle
10
Sum divided by count
Down
2
Parts per hundred
3
Lines that never intersect
7
The number representing nothing
8
Power to which a number is raised
11
Symbol representing unknown value
12
Collection of distinct elements