Question

Without doing multiplication, find the square of $29.$

• A. $841$
• B. $480$
• C. $742$
• D. $849$

Answer 1

The correct option is A $841$

It can be written as $29=20+9$

On squaring both sides, we get

${29}^2=(20+9{)}^2$

$={20}^2+2\times 20\times 9+9^2$

$=400+2\times 180+81$

$=841$

Therefore, option A is the correct answer.