1. The aspect ratio is the height-to-width ratio of an object so that the resized image does not become distorted.
2. Pixels are numbers used to set the height and width of an object.
3. 120:320
4. 400
5. Because if the width and height are not included; the image can slow down a page display because the browser must wait until the image file downloads before it can determine the image's demensions and place on the web page.
6. You can right click on an image and click on properties and the dimensions will be displayed on the file.
7. By using an alt string which is a string of text that will be displayed if image cannot.