Across
1
Exact correspondence on both sides
5
Longest side of a right triangle
6
Total distance around a shape
9
Sum divided by count
12
Rectangular array of numbers
Down
2
Distance from center to edge of circle
3
The number representing nothing
4
Corner point of a polygon
6
Parts per hundred
7
Closed shape with straight sides
8
Power to which a number is raised
10
Line touching circle at one point
11
Space between two intersecting lines