Hey,here is the answer to ur question......
1. Given: Since AD parallel BC and,AD=BC
To prove: triangle AED congruent to triangle BEC
Proof: in triangle AED and triangle BEC,we have,
AD=BC (given)
Angle DAE= Angle ECB ( since AD parallel BC=>Alternate interior angles are equal)
And,
Angle AED= Angle BEC (given)
Therefore, triangle AED congruent to triangle BEC (AAS congruence rule) .......hence proved......
Question 2.
Given: KM=JL=90 degree
JM=LM
And,
Angle JMK=angleLMK
To prove: triangle JKM congruent to triangleKLM
Proof: in triangle JKM and triangle KLM ,we have,
Angle JKM=angle LKM=90degree (given)
Angle JMK=angle LMK (given)
JM=LM (given)
=>triangle JKM congruent to triangle KLM (AAS congruence rule)......hence proved....
Question 3.
Given: AB=DE
Angle C=angleF
To prove: triangle ABC congruent to triangle DEF.
Proof: in triangle ABC and triangle DEF ,we have,
AB=DE (given)
AngleC=angleF (given)
And,
Angle BAC=angleFDE=90degree
=>triangleABC congruent to triangleDEF (AAS congruence rule).....hence proved.....
Hope this helps u........