Which congruence criterion do you use in the following?
(a) Given: AC=DF
AB=DF
BC=EF
∆ABC 
∆DEF
(b) Given: ZX=R
RQ=ZY
∠PQR = ∠XYZ
∆PQR 
∆XYZ
(c) ∠MLN = ∠FGH
∠NML = ∠GFH
ML=FG
∆LMN 
∆GFH
(d) Given: EB=DB
AE=BC
∠A = ∠C=90o
∆ABC 
∆CDB
(a) In the above given question, we have given that:
AB = DE
Also, BC = EF
And, AC = DF
Therefore, both the triangles are equal by SSS congruence criterion
As, the sides of both the triangles are equal.
(b) In the above given question, we have given that:
ZX = RP
Also,
RQ = ZY
And,
∠PQR = ∠XYZ
Therefore, both the triangles are equal by SAS congruence criterion
As,
Two sides of both the triangles are equal. Also, ∠PQR and ∠XYZ are equal.
(c) In the above given question, we have given that:
∠MLN = ∠FGH
Also,
∠NML = ∠GFH
And,
ML = FG
Therefore, both the triangles are equal by SAS congruence criterion
As, two angles and the side included between these angles of ∠LMN are equal to two angles and the side included between these angles of ∠GFH.
(d) In the above given question, we have given that:
EB = DB
Also,
AE = BC
And,
∠A = ∠C = 90o
Therefore, both the triangles are equal by RHS congruence criterion
As, two right triangles, one side and hypotenuse of the above given triangles are equal