Across
1
Steepness of a line
5
Rectangular array of numbers
6
Symbol representing unknown value
8
Divisible by two
9
Sum divided by count
10
U-shaped curve of a quadratic function
Down
1
Rectangle with four equal sides
2
Line crossing from corner to corner
3
Lines that never intersect
4
Round shape with all points equidistant
7
Longest side of a right triangle
11
Number greater than zero
12
Result of addition
13
Collection of distinct elements