Across
1
Corner point of a polygon
4
Number less than zero
5
Parts per hundred
7
Collection of distinct elements
11
Rectangular array of numbers
12
Part of a circle's circumference
Down
2
The number representing nothing
3
Longest side of a right triangle
6
Closed shape with straight sides
8
Middle value in an ordered dataset
9
Result of raising a number to an exponent
10
Proven mathematical statement