Answer:
C
Explanation:
 is the ratio of the hypotenuse of the largest triangle to that triangle's shortest side.
 is the ratio of the hypotenuse of the largest triangle to that triangle's shortest side. 
The ratio on the other side will relate corresponding sides. 
So 
 where a is the hypotenuse of the smallest triangle. The shortest leg of this triangle is r.
 where a is the hypotenuse of the smallest triangle. The shortest leg of this triangle is r.