Across
1
Part of a circle's circumference
3
Number less than zero
5
Collection of distinct elements
6
Exact correspondence on both sides
10
Distance from center to edge of circle
11
Math using letters for unknown values
12
Parts per hundred
Down
2
Value that does not change
4
Space between two intersecting lines
6
System of ordered marks for measuring
7
Sum divided by count
8
Repeated addition
9
Amount of space an object occupies