Uncle Li's family has an isosceles triangle vegetable garden, the lengths of two sides are 15 meters and 30 meters respectively. To surround the vegetable garden with a fence, what is the minimum length of the fence?
李大伯家有一块等腰三角形的菜园，其中两条边的长分别是15米和30米．要在菜园的边上围上篱笆，篱笆的长最少是多少米．
<gadget id="calculator">15 + 15 + 15 + 15 + 15</gadget>
<output>75</output>

<result>75</result>