A triangle and a parallelogram have the same base and height. The area of the triangle is 30 square centimeters. What is the area of the parallelogram in square centimeters?
一个三角形和一个平行四边形等底等高，三角形的面积是30平方厘米，平行四边形的面积是多少平方厘米．
<gadget id="calculator">30 * 2</gadget>
<output>60</output>

<result>60</result>