横向
1
Closed shape with straight sides
3
Total distance around a shape
5
Split into equal parts
6
Line touching circle at one point
7
Proven mathematical statement
8
Value that does not change
11
Visual representation of data
13
Result of addition
纵向
1
U-shaped curve of a quadratic function
2
Three-sided polygon
4
Amount of space an object occupies
9
Number less than zero
10
Rectangular array of numbers
12
Sum divided by count