Quadratic symbol-? Quadratic symbol-? You can type it out with the special symbols of QQ Pinyin input method. The specific method is as follows:

1, switch the computer input method to QQ Pinyin input method;

2. Place the mouse cursor anywhere in the status bar of QQ Pinyin Input Method, and then click the right mouse button;

3. In the pop-up page, click "Symbol Input";

4. Then click "Special Symbol";

5. After entering the symbol input device, click "Number/Unit" on the left, and then the second and fourth symbols will appear in the fifth line on the right. Click them to select an input.