Across
1
Corner point of a polygon
3
Part of a circle's circumference
4
Closed shape with straight sides
5
Steepness of a line
10
Number that divides evenly into another
11
Number greater than zero
12
Difference between highest and lowest values
13
Three-sided polygon
Down
2
Divisible by two
3
Reference line in a graph
6
Collection of distinct elements
7
Mathematical rule or equation
8
Parts per hundred
9
Mathematical statement of equality