Across
1
Result of addition
4
Space between two intersecting lines
5
Longest side of a right triangle
10
Rectangular array of numbers
11
Line crossing from corner to corner
12
Sum divided by count
13
Corner point of a polygon
14
Divisible by two
15
Difference between highest and lowest values
Down
2
Number greater than zero
3
Repeated addition
6
Symbol representing unknown value
7
Number with digits after a point
8
Part of a line with two endpoints
9
Number less than zero