ACTIVITY $2$

$2.$ Consider the array of dots in the following diagram:

Array $1,$ Array $2,$ Array $3,$ Array $4$

$2\mathrm{.}1$ What kind of numbers is shown in the above dot arrays?

$2\mathrm{.}2$ How many dots are there in the $n^{th}$ and ${20}^{th}$ dot arrays if the pattern is continued? $q,$

$2\mathrm{.}3$ How many dots will there be in the sixth and seventh arrangements? Explain how pour answer.