If an isosceles triangle is formed by 20 decimeters and 50 decimeters of wood, what is the perimeter of the obtained isosceles triangle?
用20分米和50分米的木条围成一个等腰三角形，所得等腰三角形的周长是多少？
<gadget id="calculator">50 + 50 + 20</gadget>
<output>120</output>

<result>120</result>