Question

To prove that $\Delta DEF$ and $\Delta ABC$ are congruent by SAS, what additional information is needed?

• A. $EF\cong BC$
• B. $\angle DFE\cong \angle ABC$
• C. $DE\cong AB$
• D. $\angle DFE\cong \angle ACB$

Answer 1

The correct option is C $DE\cong AB$

Given $FD=CA$ and $\angle D=\angle A$

Now for triangles to be congruent by $SAS$ we need a third side that include the given angles with the given equal sides.

So $DE=AB$ $⟹DE\cong AB$

Hence, option $C$ is correct.