Across
1
Sum divided by count
2
Result of raising a number to an exponent
6
Single numeral from 0 to 9
7
Corner point of a polygon
8
Steepness of a line
9
The number representing nothing
11
Amount of space an object occupies
12
Line touching circle at one point
13
Three-sided polygon
Down
2
Closed shape with straight sides
3
Symbol representing unknown value
4
Number greater than zero
5
Comparison of two quantities
10
Rectangle with four equal sides