Across
1
Difference between highest and lowest values
4
Value that does not change
5
Longest side of a right triangle
6
Proven mathematical statement
8
Number less than zero
10
Symbol representing unknown value
11
Steepness of a line
13
Mathematical statement of equality
Down
2
Closed shape with straight sides
3
U-shaped curve of a quadratic function
7
Corner point of a polygon
9
Amount of space an object occupies
12
Single numeral from 0 to 9