You can add/ update shapes to your section/ proposal

Rectangles (and something more than that?)

You can add rectangle to your content, resize it, colour it, add corners, border to it,rotate it.

Here is quick run-down to add rectangle to you

You can add/update other visual aspects of rectangle like border, shape, corner, shadow, etc.

Circle, Lines

Similarly you can add circle and line; change its shape, colour and other properties.