archi
Last Activity: 9 Years ago
construction: draw diagonal BD and mark intersection point of the diagonals as X.
RTP: F is mid point of AB
proof:
AX=XC=AC/2 [diagonals of a triangle bisect each other]
AC=2AX
also, AO=AC/4 [given]
or, AO=2AX/4
or,AO=AX/2................[1]
In triangle ADX
AE=DE [E is midpoint of AD]
AO=OX [from 1]
therefore,EO||DX [By mid point theorem]
In triangle AXB
AO=OX [from 1]
FO||XB [since,EO||DX]
therefore,AF=FB ….....................[2] [by converse of mid point theorem]
Therefore, F is mid point of AB [from 2]
(Hence proved)
Hope this helps!!!