Across
1
Exact correspondence on both sides
4
Lines that never intersect
5
Collection of distinct elements
8
Divisible by two
11
Steepness of a line
Down
2
Single numeral from 0 to 9
3
Longest side of a right triangle
6
The number representing nothing
7
Power to which a number is raised
9
Closed shape with straight sides
10
Rectangular array of numbers