Adding formulas to shapes in Excel can be a useful way to display calculations or data in a visual format. Here's how you can add a formula to a shape in Excel:

1. Insert the shape you want to use by going to the "Insert" tab and selecting "Shapes". Choose the shape you want to use and draw it on your worksheet.
2. Right-click on the shape and select "Format Shape" from the drop-down menu.
3. In the Format Shape pane that appears on the right side of the screen, select the "Shape Options" tab.
4. Scroll down to the "Shape Properties" section and click on the "Add Shape Data" button.
5. In the "Value" field, enter the formula you want to use. For example, if you want to display the sum of two cells, you could enter "=SUM(A1:B1)".
6. Click "OK" to close the "Shape Data" window.
7. Right-click on the shape again and select "Edit Text" from the drop-down menu.
8. In the text box that appears, type in the name of the shape or any other text you want to display alongside the formula.
9. Click outside of the text box to apply the changes.
10. The shape should now display the result of the formula you entered. If you want to update the formula, simply right-click on the shape and select "Format Shape" again, then edit the formula in the "Shape Data" window.

That's it! You can now use formulas in shapes to display calculations or data in a more visual way.