Across
1
Distance from center to edge of circle
2
U-shaped curve of a quadratic function
3
Corner point of a polygon
4
System of ordered marks for measuring
5
Exact correspondence on both sides
8
Mathematical statement of equality
12
Line touching circle at one point
Down
2
Total distance around a shape
6
Reference line in a graph
7
Symbol representing unknown value
9
Mathematical rule or equation
10
Result of addition
11
Comparison of two quantities
13
Value that does not change