Across
1
Math using letters for unknown values
5
Part of a circle's circumference
6
Mathematical rule or equation
7
Value that does not change
8
Steepness of a line
Down
2
Rectangle with four equal sides
3
Difference between highest and lowest values
4
Line crossing from corner to corner
7
Round shape with all points equidistant
9
Line touching circle at one point
10
Exact correspondence on both sides
11
Three-sided polygon