Across
1
Result of addition
3
Part of a circle's circumference
4
Corner point of a polygon
5
Difference between highest and lowest values
7
Steepness of a line
8
Three-sided polygon
9
Space between two intersecting lines
Down
1
Collection of distinct elements
2
Rectangular array of numbers
6
U-shaped curve of a quadratic function
7
Part of a line with two endpoints