Across
1
U-shaped curve of a quadratic function
6
Single numeral from 0 to 9
7
Amount of space an object occupies
8
Round shape with all points equidistant
11
Line segment connecting two circle points
Down
2
Rectangle with four equal sides
3
Proven mathematical statement
4
Sum divided by count
5
Number with digits after a point
9
System of ordered marks for measuring
10
Number greater than zero
12
Total distance around a shape