Across
1
Three-sided polygon
6
Difference between highest and lowest values
7
Proven mathematical statement
9
Math using letters for unknown values
10
Mathematical rule or equation
11
Number with digits after a point
12
Single numeral from 0 to 9
13
Part of a circle's circumference
Down
2
Split into equal parts
3
Closed shape with straight sides
4
Result of multiplication
5
Longest side of a right triangle
7
Line touching circle at one point
8
Space between two intersecting lines