Across
1
Exact correspondence on both sides
4
Line crossing from corner to corner
5
Amount of space an object occupies
6
Symbol representing unknown value
8
Parts per hundred
9
System of ordered marks for measuring
Down
2
Longest side of a right triangle
3
Single numeral from 0 to 9
7
Number less than zero
9
Rectangle with four equal sides
10
Comparison of two quantities
11
Rectangular array of numbers
12
Three-sided polygon
13
Number that divides evenly into another