Across
1
Round shape with all points equidistant
4
Reference line in a graph
5
Math using letters for unknown values
6
Number with digits after a point
7
Longest side of a right triangle
9
Power to which a number is raised
Down
2
Three-sided polygon
3
Number divisible only by 1 and itself
8
Repeated addition
10
Lines that never intersect
11
Space between two intersecting lines
12
Number less than zero