extension of a continuous function [closed]

Question

Please is it true that if $f:K\to \mathbb{R}$ is a continuous function of a comact set $K\subset\mathbb{R}^m$ then $f$ can be extended to a continuous function of some open neighbourhood of $K$?

Please if it is true give me a reference to a book.

Answer 1

You don't even need compactness: Tietze extension theorem