As far as I ah aware, they are not at all common. Drinks coasters are about the only things that I can think of.
A seven sided figure.
A seven sided shape.
Some objects that are shaped like an oval include eggs and footballs.
chicken nugget
A pencil
There are no ordinary household objects shaped like a decagon. Some glasses or vases may be decagonal in shape.
There are few household objects that are shaped like nonagons. Some coins in a few countries are, but even these are rare designs.
A seven sided figure.
what household item is the shaped like a pyramid
anything that has 7 sides
A seven sided shape.
Some objects that are shaped like an oval include eggs and footballs.
chicken nugget
eggs
A sphere.
Kites, computer screens, computer keys, and wireless routers are just a few objects shaped like quadrilaterals.
A pencil