Across
1
Longest side of a right triangle
8
Math using letters for unknown values
9
System of ordered marks for measuring
10
Number less than zero
11
Total distance around a shape
12
Number divisible only by 1 and itself
13
Result of multiplication
15
Corner point of a polygon
Down
2
Number greater than zero
3
Line touching circle at one point
4
Repeated addition
5
Three-sided polygon
6
Rectangle with four equal sides
7
Lines that never intersect
14
Proven mathematical statement