Posted by Keira on .
Length of one Total # of # of
side of pattern triangular white
(in cm) Shapes used triang
to make pattern ular
shapes
used
2 4 3
3 9 6
4 16 10
? ? ?
6 ? ?
? ? ?
? ? ?
20 ? ?
Number of gray triangular shapes used 1, 3,6,? ? ? ? ?

Math (dont want ans just help figuring this out) 
Reiny,
observation #1:
what happens when you square the numbers in the first column?
observation #2
in the third column:
second #  first # = ??
third #  second # = ??
observation #3
visualize billiard balls racked up
sum of balls after 1 row = 1
sum of balls after 2 rows = 3
sum of balls after 3 rows = 6
.... 
Math (for Reiny) 
Raquel,
Ok Reiny i get that i have to square the 1st row to come up with the 2nd row, but i still don't get how i come up with the 3rd row?

Math (dont want ans just help figuring this out) 
Damon,
2 4 3
3 9 6
4 16 10
? ? ?
6 ? ?
? ? ?
? ? ?
20 ? ?
Third column
63 = 3
106 = 4
then
155 = 5
2115 = 6
2821 = 7
so
3
6
10
15
21
28
etc