Please follow the steps below to insert an arrow shape into a worksheet:
Step 1: Click anywhere in the worksheet;
Step 2: Click the "Insert" Tab from the ribbon;
Step 3: Click "Shapes" in Illustrations section;
In Excel 2019, you need to click "Illustrations" first, then "Shapes".
Step 4: Select the down arrow shape from the shape list;
Step 5: Move to the location where you want to insert the shape. You can format or re-size the shape.