The two adjacent sides of an isosceles right triangle are 8 meters and 5 meters respectively, what is its perimeter in meters?
等腰直角三角形两条相邻的边分别是8米、5米，它的周长是多少米？
<gadget id="calculator">5 + 5 + 8</gadget>
<output>18</output>

<result>18</result>