Across
1
Rectangular array of numbers
4
Collection of distinct elements
5
Single numeral from 0 to 9
6
Round shape with all points equidistant
9
Value that does not change
11
Number that divides evenly into another
12
Total distance around a shape
Down
2
Three-sided polygon
3
Result of raising a number to an exponent
4
Result of addition
7
Corner point of a polygon
8
Line crossing from corner to corner
10
Sum divided by count