Across
1
Longest side of a right triangle
5
Part of a circle's circumference
6
Space between two intersecting lines
7
Three-sided polygon
8
Result of addition
9
Value that does not change
11
System of ordered marks for measuring
Down
2
Line touching circle at one point
3
Line crossing from corner to corner
4
Repeated addition
10
Part of a line with two endpoints
11
Exact correspondence on both sides
12
Number that divides evenly into another
13
Result of multiplication