Think you’re stuck with the out-of-the-box shapes in PowerPoint? Guess again.
Draw your shape from the closest one you can find. Then, from the Drawing Tools contextual tab, Insert Shapes group, choose the Edit Shape button. While you can use this menu to change from one established shape to another, by choosing on Edit Points you can actually make a totally different shape. Move the existing points to create your new shape, or right-click to add and delete points and segments. You can even add a curved plane on your shape even if it only has straight edges.