Question

Some numbers are given below.

$28,30,36,45,56,66,81,120,121,156$

Is there any number that can be shown as more than one shape?

Answer 1

From the given numbers, we can see,

$28=4\times 7$ i.e; Rectangular form as well as $28=1+2+3+4+5+6+7$i.e.; Triangular form

$36=6\times 6$ i.e; Square form as well as $36=1+2+3+4+5+6+7+8$ i.e.; Triangular form and $36=12\times 3$ i.e; Rectangular form

$45=9\times 5$ i.e; Rectangular form as well as $45=1+2+3+4+5+6+7+8+9$ i.e.; Triangular form

$81=9\times 9$ i.e; Square form as well as $81=27\times 3$ i.e; Rectangular form

$120=12\times 10$ i.e; Rectangular form as well as $120=1+2+3+4+5+6+7+8+9+10+11+12+13+14+15$ i.e.; Triangular form.

Hence, we can say that $28,36,45,81,120$can be written in more than one shape.