Answer: C) HF is 4 units and GH is 2 units.
Explanation:
The SSS similarity theorem says that if the side-lengths of the corresponding sides of two triangles are proportional then the triangles are similar.
In ΔDFE and ΔGFH ,
DG = 15, GF = 5, EH = 12, and DE = 8.
To prove ΔDFE and ΔGFH are similar by using SSS similarity theorem we need :-
![(DF)/(GF)=(FE)/(FH)=(DE)/(GH)\\\\\Rightarrow(DG+GF)/(GF)=(FH+EH)/(FH)=(DE)/(GH)\\\\\Rightarrow(5+15)/(5)=(12+HF)/(FH)=(8)/(GH)\\\\\Rightarrow(20)/(5)=(12+HF)/(FH)\ and\ (20)/(5)=(8)/(GH)\\\\\Rightarrrow4HF=12+HF\ and\ GH=(8)/(4)\\\\\Rightarrow3HF=12\ and\ GH=2\\\\\Rightarrow HF=4\ and\ GH=2](https://img.qammunity.org/2019/formulas/mathematics/middle-school/yb299m74mekqexpz5lm7gzy23vui9dfb0i.png)
Hence, To prove that △DFE ~ △GFH by the SSS similarity theorem using the information provided in the diagram, it would be enough additional information to know that HF is 4 units and GH is 2 units.