Across
1
Total distance around a shape
5
Sum divided by count
6
Steepness of a line
7
Round shape with all points equidistant
9
Reference line in a graph
11
Symbol representing unknown value
Down
2
Corner point of a polygon
3
Repeated addition
4
Three-sided polygon
5
Part of a circle's circumference
6
System of ordered marks for measuring
8
Number greater than zero
10
Number divisible only by 1 and itself