Excel has many Shapes to choose from, but sometimes the Shape you need is not in the gallery. In such a case, you may be able to modify one of the existing shapes using one of these techniques:

Rotate the Shape:
When you select a Shape, it displays a small green dot. Click and drag this dot to rotate the Shape.

Group multiple Shapes:
You may be able to create the Shape you need by combining two or more Shapes and then grouping them.

Reconfigure the Shape:
Many of the Shapes display one or more small yellow diamonds when the Shape is selected. You can click and drag this diamond to change the Shape's outline. The exact behavior varies with the AutoShape, so you should experiment and see what happens.

Create a Freeform Shape:
Select the Freeform Shape (in the Lines category of the Shapes gallery) to create a custom Shape.

Convert an existing Shape to a Freeform Shape:
If an existing Shape is close to what you want, convert it to a Freeform Shape and then edit its points. Select the Shape and choose Drawing Tools Format Insert Shapes Edit Shape Convert To Freeform. Then, with the shape still selected, choose Drawing Tools Format Insert Shapes Edit Shape Edit Points. You can then drag the points to reconfigure the Shape.

Regards,
Jerry