At 3:00 pm on March 28, the ratio of the height of the school flagpole to its shadow length was 4:1. The shadow length of the flagpole was measured to be 3m at that time. How many meters is the actual height of the school flagpole?
3月28日下午三点，学校旗杆的高度与它的影长的比是4：1，当时测得旗杆的影长是3m，学校旗杆的实际高度是多少米？
<gadget id="calculator">4 * 3</gadget>
<output>12</output>

<result>12</result>