Across
1
Number less than zero
4
U-shaped curve of a quadratic function
6
Total distance around a shape
7
Corner point of a polygon
10
Space between two intersecting lines
11
Lines that never intersect
Down
2
Collection of distinct elements
3
Value that does not change
4
Parts per hundred
5
Distance from center to edge of circle
8
Steepness of a line
9
Three-sided polygon