Across
1
Part of a circle's circumference
3
Longest side of a right triangle
4
Symbol representing unknown value
5
Divisible by two
6
Reference line in a graph
8
Rectangle with four equal sides
10
Total distance around a shape
11
Sum divided by count
Down
2
Middle value in an ordered dataset
4
Corner point of a polygon
7
Number greater than zero
8
System of ordered marks for measuring
9
Number less than zero
12
The number representing nothing