Across
1
Single numeral from 0 to 9
4
Part of a circle's circumference
5
Symbol representing unknown value
6
Lines that never intersect
Down
2
Round shape with all points equidistant
3
Distance from center to edge of circle
7
Sum divided by count
8
Closed shape with straight sides
9
Line touching circle at one point
10
System of ordered marks for measuring
11
Corner point of a polygon