Integer Triangles Investigation – Part 1

just square the number of its sides

By direct counting, the number of circles is 16.

It is going according to the order of the square numbers

they in order of consecutive squares...so (4)*2 = 16

It is the siries of squares of all natural numbers. ( 1, 2, 3, 4)

add odd no.s:1+3+5+7

The dots of the triangles are in a series of squares of natural numbers.

$1,4,9,16,....$

Thus, the answer is: $4^{th}$ triangle $=\boxed{16}$ dots

answer is $\boxed{16}$