Across
1
Mathematical statement of equality
4
Closed shape with straight sides
6
Three-sided polygon
7
Reference line in a graph
9
Split into equal parts
11
Steepness of a line
Down
2
Single numeral from 0 to 9
3
Part of a circle's circumference
4
Lines that never intersect
5
Line segment connecting two circle points
8
Symbol representing unknown value
10
Result of multiplication
12
Round shape with all points equidistant