There is a triangular green belt in the school. The ratio of the three sides is 3:4:5. The longest side is known to be 45 meters. If a fence is used to surround this green belt, how many meters of fence are needed?
学校有一块三角形绿化带，三条边的比是3：4：5，已知最长边是45米，如果给这块绿化带围上篱笆，需要多少米篱笆？
<gadget id="calculator">45 / 5</gadget>
<output>9</output>

<gadget id="calculator">9 * 4</gadget>
<output>36</output>

<gadget id="calculator">9 * 3</gadget>
<output>27</output>

<gadget id="calculator">45 + 36 + 27</gadget>
<output>108</output>

<result>108</result>