Step-by-step explanation:
[tex]\bf a=2\cdot (1+2+3....224)+225[/tex]
[tex]\bf a=2\cdot \big[(1+224)\cdot 224 : 2\big]+225[/tex]
[tex]\bf a=2\cdot \big(225\cdot 224 : 2\big)+225[/tex]
[tex]\bf a=2\cdot \big(225\cdot 112\big)+225[/tex]
[tex]\bf a=2\cdot 25200+225[/tex]
[tex]\bf a=50400+225[/tex]
[tex]\bf a=50625[/tex]
[tex]\red{\boxed{\bf a=225^{2} \implies ~patrat ~perfect}}[/tex]
[tex]\bf \sqrt{a}=\sqrt{225^{2}} \implies \purple{\boxed{\bf a = 225}}[/tex]
