横向
1
Math using letters for unknown values
2
Closed shape with straight sides
6
Line segment connecting two circle points
纵向
1
Part of a circle's circumference
2
U-shaped curve of a quadratic function
3
Space between two intersecting lines
4
Comparison of two quantities
5
Longest side of a right triangle
7
Single numeral from 0 to 9
8
Repeated addition
