Customise your own chapter style

Question

I'm looking to personalise my own chapter style as shown in the photo.

Despite a few articles on the subject I haven't managed to fully understand how it works and what needs to be done to achieve the following result. My document is a report.

Answer 1

This is quite easy using a configurable class like the KOMA-Script classes scrreprt, which is another report class, or scrbook, which is another book class:

\documentclass[chapterprefix]{scrreprt}% or scrbook
\usepackage{libertinus}% use any scalable font you want
\setkomafont{chapter}{\normalfont\huge}% Font of the chapter title
\setkomafont{chapterprefix}{\normalfont\fontsize{48}{48}\selectfont}% Font of the chapter number
\renewcommand*{\chapterformat}{\thechapter}% Use just the chapter number without any prefix in the number line
\let\raggedchapter\centering% horizontal centering of chapter headings
\usepackage{lipsum}\setcounter{chapter}{2}% Only for demonstration
\begin{document}
\chapter{Methodology}
\lipsum[1]
\end{document}

Several more configuration options are provides, e.g., to modify the spaces above the number, below the number and below the title. See the KOMA-Script manuals for more information.

Similar things can be done using, e.g., memoir class or package sectsty or titlesec. Please see the manuals for more information and ask a question with minimal working example if you have problems implementing your requests.