Across
1
Space between two intersecting lines
4
Divisible by two
5
Round shape with all points equidistant
6
Power to which a number is raised
7
Result of multiplication
8
Comparison of two quantities
9
Sum divided by count
11
Lines that never intersect
12
The number representing nothing
Down
2
Three-sided polygon
3
Symbol representing unknown value
10
Proven mathematical statement
11
Parts per hundred
13
Total distance around a shape