Across
1
Total distance around a shape
3
System of ordered marks for measuring
6
Round shape with all points equidistant
7
Line segment connecting two circle points
8
Amount of space an object occupies
9
Line crossing from corner to corner
10
Corner point of a polygon
11
Number divisible only by 1 and itself
Down
2
Rectangle with four equal sides
3
Exact correspondence on both sides
4
Number that divides evenly into another
5
Math using letters for unknown values
6
Value that does not change
10
Symbol representing unknown value
12
Proven mathematical statement