Across
1
Closed shape with straight sides
4
Single numeral from 0 to 9
5
Collection of distinct elements
6
Space between two intersecting lines
7
Round shape with all points equidistant
8
Parts per hundred
9
The number representing nothing
11
Result of addition
12
Lines that never intersect
Down
1
Result of raising a number to an exponent
2
Three-sided polygon
3
Power to which a number is raised
7
Line segment connecting two circle points
10
Longest side of a right triangle