Across
1
Symbol representing unknown value
6
Corner point of a polygon
7
Math using letters for unknown values
8
Space between two intersecting lines
Down
2
Rectangle with four equal sides
3
Repeated addition
4
Divisible by two
5
Lines that never intersect
9
Collection of distinct elements
10
Number with digits after a point
11
Mathematical rule or equation
12
Middle value in an ordered dataset