For the first question
part ii, TFA similar to TAE
TF/TA=TA/TE ==>TE*TF=TA*TA (1)
But TA and TB are tangents from an external point
therefore TA=TB, sub into (1) and part ii is done
part iii, use the result from ii
TE*TF=TB*TB ==> TE/TB=TB/TF
and <FTB is the common angle
therefore...