Across
1
Line touching circle at one point
4
The number representing nothing
5
U-shaped curve of a quadratic function
6
Number divisible only by 1 and itself
11
Sum divided by count
12
Space between two intersecting lines
Down
2
Number less than zero
3
Round shape with all points equidistant
7
Steepness of a line
8
Power to which a number is raised
9
Comparison of two quantities
10
Rectangle with four equal sides
13
Part of a line with two endpoints