Across
1
Rectangle with four equal sides
3
Total distance around a shape
5
Round shape with all points equidistant
7
Symbol representing unknown value
10
The number representing nothing
12
Result of addition
13
Math using letters for unknown values
Down
2
U-shaped curve of a quadratic function
3
Result of raising a number to an exponent
4
Corner point of a polygon
6
Reference line in a graph
8
Three-sided polygon
9
Part of a line with two endpoints
11
Difference between highest and lowest values