A rectangle can be formed by using 2 sticks of 13 cm and 2 sticks of 16 cm. What is the perimeter of this rectangle in centimeters?
用2根13厘米的小棒和2根16厘米的小棒可以围成一个长方形，这个长方形的周长是多少厘米．
<gadget id="calculator">16 + 13</gadget>
<output>29</output>

<gadget id="calculator">29 * 2</gadget>
<output>58</output>

<result>58</result>