+0  
 
0
144
1
avatar





 

 Apr 14, 2020
 #1
avatar
+1

Since triangle ABD and triangle DCA have their vertices on the same line BC and have common base AD, thus both are equal in area and congruent (It is a theorem)

It also follows that AD parallel to BC since vertices of both triangles are on BC and they have the same base at AD. 

Since AD parallel to BC, By alternate angles

 Apr 15, 2020

10 Online Users

avatar