I am going to elaborate you how to embed a pdf file in gmail in this article.
You have to follow the below mentioned step.
Step 1: Open your web browser (Safari, Google Chrome, Mozilla, etc).
Step 2: Type https://www.gmail.com in your web browser.
Step 3: Login with your login credentials (Gmail Email Id and Password).
Step 4: Now at the left hand side there is an option of Compose, click on it.
Step 5: Now a screen of New Message will appear.
Step 6: Now at the bottom there is a pin like option to attach a document ,image etc. Click it
Step 7: Now you can attach your pdf by selecting the file in the directory where it is saved.
Step 8: Enter the email id of the person, organization in To option and send the pdf.