Across
1
Parts per hundred
4
Number less than zero
5
Amount of space an object occupies
6
Math using letters for unknown values
8
Exact correspondence on both sides
9
Round shape with all points equidistant
10
Steepness of a line
Down
1
Lines that never intersect
2
Closed shape with straight sides
3
The number representing nothing
7
Rectangle with four equal sides