Do you draw a circle on the spreadsheet? If there is, the painting method is the same as that on word.

Steps:

Insert → Picture → AutoShape → Select "Circle". At this time, the mouse becomes a "+"shape, and at the same time, hold down the "shift" key → the circle drawn in this way is a perfect circle.

You can also draw a circle (but not a perfect circle) when the mouse is in a "+"shape, then right-click, select a format graphic, select a size, set the height and width to be the same, and then click OK.

If the above answers are helpful to you, please adopt them and wish you success! )