The length of A wooden strip is 9 cm, and the length of B wooden strip is 1/2 of that of A wooden strip. A total of three of these two kinds of wooden strips are used to form an isosceles triangle. What is the perimeter of the isosceles triangle in centimeters.
甲木条长9厘米，乙木条长是甲木条的(1/2)，用这两种木条共三根围成一个等腰三角形，等腰三角形的周长是多少厘米．
<gadget id="calculator">1 / 2</gadget>
<output>1/2 = around 0.5</output>

<gadget id="calculator">9 * (1/2)</gadget>
<output>9/2 = around 4.5</output>

<gadget id="calculator">(9/2) + (9/2) + (9/2) + (9/2) + (9/2)</gadget>
<output>45/2 = around 22.5</output>

<result>45/2 = around 22.5</result>