横向
1
Exact correspondence on both sides
2
Corner point of a polygon
5
The number representing nothing
6
Rectangle with four equal sides
7
Mathematical statement of equality
8
Line touching circle at one point
10
U-shaped curve of a quadratic function
12
Total distance around a shape
纵向
1
Collection of distinct elements
2
Symbol representing unknown value
3
Sum divided by count
4
Middle value in an ordered dataset
9
Number with digits after a point
11
Split into equal parts
13
Number less than zero