Across
1
Line crossing from corner to corner
2
Part of a line with two endpoints
4
Three-sided polygon
5
Divisible by two
6
Corner point of a polygon
12
Result of addition
Down
1
Single numeral from 0 to 9
2
Rectangle with four equal sides
3
Math using letters for unknown values
7
Comparison of two quantities
8
Distance from center to edge of circle
9
System of ordered marks for measuring
10
Steepness of a line
11
Value that does not change