Across
1
Closed shape with straight sides
4
Line crossing from corner to corner
5
Reference line in a graph
6
Part of a line with two endpoints
7
Number less than zero
11
Space between two intersecting lines
13
Longest side of a right triangle
Down
1
Result of raising a number to an exponent
2
Comparison of two quantities
3
Mathematical rule or equation
6
Result of addition
8
Number greater than zero
9
Lines that never intersect
10
Sum divided by count
12
Collection of distinct elements