There are three methods to resize your image:
Method 1: Enter the size of the height and width of the image when inserting the image into the post.
If you leave the height and width boxes blank, it will show the original size of the image.
Method 2: Click the image and drag the borderline to resize it after the image appears in the editor.
Please note that this method is only available to Firefox and IE browser. If you're using Chrome or Safari, you may try the other two methods.
Method 3: Click the “source code” icon on the edit section to show the HTML codes., then enter the width and height of the image.