what happens (in general) if you do one enlargement scale factor 2 from one centre and then enlarge the resultant shape from another centre, also scale factor 2?
the powerpoint is here
it needs to be downloaded for the animations to work
the third triangle can also be obtained from the first via an enlargement
what will the scale factor be and where will the centre of enlargement be?
check this with the ones drawn above
what happens with different scale factors?
the proof of the relationship can be done using vectors
this was done by James Pearce, of Mathspad fame
many thanks for the very neat vector proof, which he did generalise