Hello, I have a form of google that I want for a page with the formatting of 1280 * 800 and the problem and that does not occupy the page completely always hide or at the end of the form or iframe in the iframe it hides content I want it to occupy the potion of the page in width and height, can help me or indicate me some way, even in css I tried to correct the positioning but do not know do not know why, thank you.
<!doctype html>
<html>
<head>
<meta charset="utf-8">
<title>teste</title>
</head>
<body>
<iframe src="https://docs.google.com/forms/d/e/1FAIpQLSd4pzJ9kRydc-UVkEkm9xKDZjF0S3Earn-Wjcbh8FEAlYnkXA/viewform?embedded=true"width="100%" height="825" frameborder="0" marginheight="0" marginwidth="0">Loading...</iframe>
</body>
</html>