Across
1
Part of a whole number
4
Collection of distinct elements
6
Part of a circle's circumference
8
U-shaped curve of a quadratic function
9
Parts per hundred
10
Exact correspondence on both sides
12
Space between two intersecting lines
Down
2
Total distance around a shape
3
Repeated addition
5
Difference between highest and lowest values
7
Line segment connecting two circle points
11
Proven mathematical statement