we know that
Right triangles PBM and MTF are similar
because
angle PMB=angle TMF
and
angle BPM=angle FTM
and
angle B =angle F=90 degrees
so
corresponding sides are
BM and MF
PB and TF
PM and MT
(PB/TF)=BM/MF
solve for PB
PB=(TF*BM)/MF
where
TF=6ft
BM=20 ft
MF=3 ft
so
PB=(6*20)/3------> 40 ft
the answer is
the height of the peak is 40 ft