The six principles of the Constitution are popular sovereignty, federalism, separation of powers, checks and balances, judicial review, and limited government. These principles are important because they create balance between the people and the government, making sure that the government never becomes too powerful.
Example of popular sovereignty- The people are the only source of government power (“We the people..”)
Example of limited government- The government must obey the law aka constitutionalism (Rule of law)
Example of separation of powers- Legislative branch, Executive branch, Judicial branch
Example of checks and balances- Each branch is tied together by checks and balances
Example of Judicial review- Marbury vs Madison (1803). The Supreme Court established the power of judicial review
Example of Federalism- Freeways. They are owned and operated by the states, but the federal government sets down guidelines that all states must follow and also provides funding.
hope this helps :)