Across
1
Part of a line with two endpoints
5
Round shape with all points equidistant
6
Space between two intersecting lines
8
Closed shape with straight sides
11
System of ordered marks for measuring
13
Lines that never intersect
Down
1
Collection of distinct elements
2
Single numeral from 0 to 9
3
Repeated addition
4
Mathematical statement of equality
7
Difference between highest and lowest values
9
U-shaped curve of a quadratic function
10
Part of a circle's circumference
12
Steepness of a line
14
Part of a whole number