Steps of finding out square by diagonal method.
⇒ Form a square and divide it into sub-squares based on the number of digits, row and column wise. Then draw the diagonals of the smaller squares.
⇒ Multiply each digit on the left of the square with each digit on the top of the column one by one.
⇒ If the product has a single digit number, write it below the diagonal. If it has two digit number, write the tens digit in upper part of the diagonal and units digit in the lower part of the diagonal.
⇒ Add all the digits diagonally starting from the lowest diagonal.
⇒ Underline all the units' digits and carry over the other digit to the next and add the carry to the next number.
⇒ After completing this write down all the underlined digits. This number will be the square of the given number.
∴ 1712=29241