Across
1
Symbol representing unknown value
5
Power to which a number is raised
6
Round shape with all points equidistant
7
The number representing nothing
8
Distance from center to edge of circle
Down
2
Three-sided polygon
3
Result of raising a number to an exponent
4
Rectangle with four equal sides
9
Number with digits after a point
10
Divisible by two
11
Part of a circle's circumference