Step 1: Get the embed code for the quiz you want to embed

Step 2: Login to Google sites and click on the selected site link or create a new site such as "Classroom site".

Step 3: Click on the category in which you want to embed the quiz such as "Class Announcements".

Step 4: Click on "New Post".

Step 5: Click on "HTML" mode.

Step 6: Paste Embed code of quiz here and click on "Update".

Step 7: Click on "Save" to publish your quiz and you are done.