Uncle Wang’s family built a new house. They originally planned to open a window with a length of 1 meter and a height of 7.5 decimeters on the north wall. Later, they thought the window was too small, so they increased the length and height by 2 decimeters. Now the window area is How many square decimeters have been increased from the original.
王大爷家新盖了一间房子，原打算在北墙上开一个长1米，高7.5分米的窗户，后来嫌窗户小，又把长和高都增加了2分米，现在窗户的面积比原来增加了多少平方分米．
<gadget id="calculator">1 * 10</gadget>
<output>10</output>

<gadget id="calculator">10 + 2</gadget>
<output>12</output>

<gadget id="calculator">7.5 + 2</gadget>
<output>9.5</output>

<gadget id="calculator">12 * 9.5</gadget>
<output>114</output>

<gadget id="calculator">1 * 10 * 7.5</gadget>
<output>75</output>

<gadget id="calculator">114 - 75</gadget>
<output>39</output>

<result>39</result>