You can resize a picture in Word without having to use another photo-editing tool.
You may want to resize a picture because:
Word has the tools to resize your picture.
The advantage of using the Word picture editing tools is that you can immediately see the effect in your Word document.
If you do not like it, you can undo or easily revert to the previous setting.
Dragging the handles in Figure 1 relies on you making a judgement on the size. This may be okay for your needs.
But you may want to have a picture an exact size, for example, to make all the pictures in your document the same size.
Figure 2 shows you how to resize a picture in Word exactly.
Note that when one measurement (e.g., the height) is changed, the other changes automatically. This is to keep the proportion of height and width the same (i.e., the aspect ratio), otherwise the picture could be distorted.
Figure 3 shows the original picture (in Figure 2) resized from 5 inches to 4 inches (or the equivalent in centimeters).
More resize options are available in the Layout dialog box.
Select the bottom right hand arrow in the Size box (see Figure 3).
The "Lock aspect ratio" needs to be selected to keep the picture in proportion.
If not, the picture could be distorted. Deselect if you do not want the proportions to be kept.
Figure 5 shows the Eiffel Tower picture reduced to 80% of the original size.
The "Relative to original picture size" option (see Figure 4) is selected by default.
This means every scale change (e.g., 75%, 50%) is against the original picture size.
For example, the left hand picture in Figure 6 is the original and the middle figure is 75% of the original.
A 50% resizing of the middle figure is actually 50% of the original picture.
If the "Relative to original picture size" option is not selected, any scaling is applied to that picture and not to the original picture.
For example, 50% rescaling to the middle picture is applied against that picture (and not the original as in Figure 6).
The difference between the two can be seen in the right hand pictures in Figures 6 and 7.
You can easily rotate a picture in Word as follows:
Rotate the picture until you are happy with its orientation.
You can be more precise about the rotation by specifying exactly the degree of rotation instead of relying on a visual estimate.
Specify the degree of rotation as follows:
You do not need photo-editing software to resize a picture in Word. The same applies to rotating a picture.
The Word picture editing tools are sufficient in many cases, and are all that you need.
As stated above, the advantage of using the Word picture editing tools is that you can see immediately how the edit affects your Word document. You can undo the edit or revert to the previous setting easily.
This is easier and quicker than using another program to resize (or rotate) the picture and then copying or importing into your Word document.
Reference - change the size of a picture.