If, then ∆ABC and ∆EFD are congruent by the ASA criterion. If, then ∆ABC and ∆EFD are congruent by the SAS criterion. NextReset

Yes. bit tricky to explain. hope u will get this.

By ASA

when two angles are same and one side so we can find the third angle of a triangle

so that third angle is also going to the same angle with other triangle, mean atlast this angle is congruent with other triangle.

Now u can get the other sides as u know one side, by laws of sin

that will also work same for other triangle. same side and angles

By SAS u know that triangle has two side congruent and angle between them, ultimately we have proved that earlier all sides are equal by ASA,