The upper base of a trapezoid is 4.5 cm, the lower base is 5.2 cm, and the height is 5 cm. What is its area in square centimeters?
一个梯形的上底是4.5厘米，下底是5.2厘米，高是5厘米，它的面积是多少平方厘米．
<gadget id="calculator">4.5 + 5.2</gadget>
<output>9.7</output>

<gadget id="calculator">5 / 2</gadget>
<output>5/2 = around 2.5</output>

<gadget id="calculator">9.7 * (5/2)</gadget>
<output>24.25</output>

<result>24.25</result>