Across
1
Symbol representing unknown value
3
Single numeral from 0 to 9
5
Part of a line with two endpoints
6
Number divisible only by 1 and itself
7
Space between two intersecting lines
8
Sum divided by count
9
Divisible by two
Down
1
Corner point of a polygon
2
Distance from center to edge of circle
4
Lines that never intersect
5
Rectangle with four equal sides