Across
1
Math using letters for unknown values
5
Divisible by two
6
Rectangle with four equal sides
9
Line crossing from corner to corner
10
Result of multiplication
11
Proven mathematical statement
Down
2
Three-sided polygon
3
Single numeral from 0 to 9
4
Part of a circle's circumference
7
Sum divided by count
8
Repeated addition
9
Split into equal parts