Across
1
Corner point of a polygon
4
Sum divided by count
5
Collection of distinct elements
6
Symbol representing unknown value
7
Part of a whole number
10
Exact correspondence on both sides
Down
2
Number with digits after a point
3
Parts per hundred
8
Reference line in a graph
9
Proven mathematical statement
10
Steepness of a line
11
Three-sided polygon
12
Space between two intersecting lines
13
Closed shape with straight sides