There is a rectangular glass with a length of 12 cm and a width of 8 cm. If this glass is used to form a square, how many pieces are needed at least? Please briefly explain the reason.
有一种长12厘米，宽8厘米的长方形玻璃，如果用这种玻璃拼成一个正方形，最少需要几块？请简单说明理由．
<gadget id="calculator">24 / 12</gadget>
<output>2</output>

<gadget id="calculator">24 / 8</gadget>
<output>3</output>

<gadget id="calculator">2 * 3</gadget>
<output>6</output>

<result>6</result>