Across
1
System of ordered marks for measuring
4
Three-sided polygon
8
Total distance around a shape
9
Symbol representing unknown value
Down
1
Rectangle with four equal sides
2
Corner point of a polygon
3
Comparison of two quantities
5
Repeated addition
6
Mathematical statement of equality
7
Lines that never intersect
10
Number divisible only by 1 and itself
11
Sum divided by count