Across
1
Single numeral from 0 to 9
4
Round shape with all points equidistant
6
Space between two intersecting lines
7
Steepness of a line
8
System of ordered marks for measuring
9
Three-sided polygon
10
Amount of space an object occupies
11
Comparison of two quantities
Down
2
Proven mathematical statement
3
Repeated addition
5
Sum divided by count