Across
1
The number representing nothing
2
Exact correspondence on both sides
3
Number less than zero
7
Corner point of a polygon
8
Proven mathematical statement
Down
2
System of ordered marks for measuring
4
Three-sided polygon
5
Symbol representing unknown value
6
Divisible by two
9
Distance from center to edge of circle
10
Line segment connecting two circle points
11
Result of raising a number to an exponent