Across
1
Longest side of a right triangle
5
Single numeral from 0 to 9
7
Lines that never intersect
8
Result of raising a number to an exponent
11
Round shape with all points equidistant
12
Line crossing from corner to corner
Down
2
Parts per hundred
3
Space between two intersecting lines
4
Line touching circle at one point
6
System of ordered marks for measuring
9
Value that does not change
10
The number representing nothing