Across
1
Mathematical rule or equation
3
Corner point of a polygon
5
Lines that never intersect
6
Parts per hundred
7
Steepness of a line
11
U-shaped curve of a quadratic function
12
The number representing nothing
Down
2
Value that does not change
4
Line crossing from corner to corner
8
Collection of distinct elements
9
Comparison of two quantities
10
Space between two intersecting lines