A rectangular iron sheet is 13 cm long and 7 cm wide. Cut out the largest square from it. What is the area of this square in square centimeters?
一块长方形铁皮，长13厘米，宽7厘米，从它上面剪下一个最大的正方形，这个正方形的面积是多少平方厘米．
<gadget id="calculator">7 * 7</gadget>
<output>49</output>

<result>49</result>