How do you change the image size


#1

please help me i don't know how to change the image size

here is my code for the image i want to change the size of:
(and the image)




The 'U' Mine (1 block of emerald for $100,000,000. rankup is about 100,000,000,000 )



#2

whoops here is the code:

<div class="col-md-4">
<div class="thumbnail">
  <img src="http://static.planetminecraft.com/files/resource_media/screenshot/1422/2014-05-26_183720.jpg" height="900" width="1000">
  <p>The 'U' Mine (1 block of emerald for $100,000,000. rankup is about 100,000,000,000 )</p>
</div>