Across
1
Space between two intersecting lines
4
Collection of distinct elements
5
Closed shape with straight sides
6
Rectangle with four equal sides
7
Repeated addition
8
System of ordered marks for measuring
11
Difference between highest and lowest values
12
Mathematical statement of equality
Down
2
Line touching circle at one point
3
U-shaped curve of a quadratic function
9
Divisible by two
10
Number less than zero