Across
1
Longest side of a right triangle
7
Corner point of a polygon
8
Sum divided by count
13
Rectangular array of numbers
Down
2
Line touching circle at one point
3
Total distance around a shape
4
System of ordered marks for measuring
5
Number divisible only by 1 and itself
6
The number representing nothing
9
Part of a line with two endpoints
10
Divisible by two
11
Mathematical statement of equality
12
Number less than zero