Across
1
Mathematical statement of equality
5
Lines that never intersect
6
Result of addition
8
Part of a circle's circumference
9
Longest side of a right triangle
11
Reference line in a graph
12
Sum divided by count
Down
2
Space between two intersecting lines
3
Three-sided polygon
4
Middle value in an ordered dataset
6
System of ordered marks for measuring
7
Symbol representing unknown value
10
Number less than zero
13
Result of multiplication