Across
1
Longest side of a right triangle
4
Steepness of a line
5
Distance from center to edge of circle
8
Value that does not change
9
Total distance around a shape
10
The number representing nothing
11
Math using letters for unknown values
Down
2
Symbol representing unknown value
3
Result of addition
4
Rectangle with four equal sides
6
Result of multiplication
7
Line segment connecting two circle points
12
Line touching circle at one point
13
System of ordered marks for measuring