Make a triangular red scarf with a base length of 90 cm and a height of 28 cm. What is the minimum amount of fabric needed?
做一个三角形的红领巾，底边长90厘米，高28厘米．至少需要多少布料？
<gadget id="calculator">28 / 2</gadget>
<output>14</output>

<gadget id="calculator">90 * 14</gadget>
<output>1_260</output>

<result>1_260</result>