The perimeter of a square is equal to that of an isosceles triangle. The length of the side of this triangle is 7.5 cm, and the length of the base is 6 cm less than the sum of the two sides. What is the area of the square?
一个正方形与一个等腰三角形的周长相等，这个三角形的腰长为7.5厘米，底边长比两腰之和少6厘米，这个正方形的面积是多少．
<gadget id="calculator">15 + 11</gadget>
<output>26</output>

<gadget id="calculator">26 / 4</gadget>
<output>13/2 = around 6.5</output>

<gadget id="calculator">(13/2) * (13/2)</gadget>
<output>169/4 = around 42.25</output>

<result>169/4 = around 42.25</result>