A rectangle and a triangle have the same base and height, and the area of the triangle is 30 square centimeters, what is the area of the rectangle?
一个长方形和一个三角形等底等高，已知三角形的面积是30平方厘米，长方形的面积是多少？
<gadget id="calculator">30 * 2</gadget>
<output>60</output>

<result>60</result>