Across
1
System of ordered marks for measuring
3
Part of a circle's circumference
4
Steepness of a line
5
Line crossing from corner to corner
8
Mathematical statement of equality
10
Repeated addition
Down
2
Number with digits after a point
4
Rectangle with four equal sides
6
Total distance around a shape
7
The number representing nothing
9
Visual representation of data
11
Sum divided by count
12
Part of a line with two endpoints