Across
1
Round shape with all points equidistant
2
Collection of distinct elements
4
Number divisible only by 1 and itself
5
Three-sided polygon
7
Mathematical statement of equality
10
Mathematical rule or equation
Down
2
Exact correspondence on both sides
3
The number representing nothing
6
U-shaped curve of a quadratic function
8
Part of a circle's circumference
9
Part of a line with two endpoints
11
Closed shape with straight sides