What are convex and regular polyhedrons ?

Kindly, refer to the below link for similar query,
https://www.meritnation.com/ask-answer/question/what-are-convex-polyhedrons/visualising-solid-shapes/4134645

https://www.meritnation.com/ask-answer/question/defination-of-regular-polyhedron/visualising-solid-shapes/681160
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