There are two identical semicircular lawns in the park in the middle of the street, and their perimeters are both 25.7m. What is the total area of these two lawns?
街心公园有两块一样的半圆形草坪，它们的周长都是25.7m，这两块草坪的总面积是多少？
<gadget id="calculator">10 / 2</gadget>
<output>5</output>

<gadget id="calculator">5 ** 2</gadget>
<output>25</output>

<gadget id="calculator">3.14 * 25</gadget>
<output>78.5</output>

<result>78.5</result>