the complete question in the attached figure
we know that
From the given triangle, we can see that the lengths of the arms of the right-angle are 
 units and 
 
 
 units. (the shortest side is 
 
 
The second triangle is described as being similar, which means its sides are in the same ratio as the first, but the orientation can be different.
From the two given points the shortest side is horizontal and 
the length is equal to

This means that the sides of the second triangle are all 

 times as long as the first

The second side of the second triangle will be

There are 
 possible positions for the third point. 
 units up or down from 
 or
 

 to form a right-angle.
The options are therefore:

Only the point 
 is one of the options given
therefore
the answer is
the third point is 
