Across
1
Part of a circle's circumference
3
Divisible by two
5
Math using letters for unknown values
7
Total distance around a shape
8
Split into equal parts
9
Difference between highest and lowest values
Down
2
Symbol representing unknown value
4
Line segment connecting two circle points
6
Space between two intersecting lines
10
Single numeral from 0 to 9
11
Value that does not change
12
Round shape with all points equidistant
13
Line touching circle at one point