Across
1
Line crossing from corner to corner
4
Corner point of a polygon
5
Value that does not change
6
Difference between highest and lowest values
7
Total distance around a shape
9
Mathematical statement of equality
10
Comparison of two quantities
11
Reference line in a graph
13
Proven mathematical statement
Down
2
Three-sided polygon
3
Mathematical rule or equation
5
Round shape with all points equidistant
8
Lines that never intersect
12
The number representing nothing