Problem
\( 2(1+\sqrt{2}) 70^{2} \)
Solution
Step 1 ：\( 2(1+\sqrt{2}) 70^{2} \)
Step 2 ：\( 2(1+\sqrt{2}) \times 4900 \)
Step 3 ：\( 9800 + 13856\sqrt{2} \)
Step 1 ：\( 2(1+\sqrt{2}) 70^{2} \)
Step 2 ：\( 2(1+\sqrt{2}) \times 4900 \)
Step 3 ：\( 9800 + 13856\sqrt{2} \)
