Across
1
Steepness of a line
4
Line crossing from corner to corner
5
Value that does not change
6
Three-sided polygon
9
Result of addition
11
Rectangle with four equal sides
Down
2
Sum divided by count
3
Mathematical rule or equation
7
Total distance around a shape
8
Corner point of a polygon
10
Reference line in a graph
12
Part of a circle's circumference