There is a right triangle, the lengths of the three sides are 0.3 decimeter, 0.5 decimeter, 0.4 decimeter respectively, what is the perimeter of this triangle?
有一个直角三角形，三条边的长度分别为0.3分米、0.5分米、0.4分米，这个三角形的周长是多少分米．
<gadget id="calculator">0.3 + 0.5 + 0.4</gadget>
<output>1.2</output>

<result>1.2</result>