Question

A(4,2) B(1,4) C(6,5)

Answer 1

One has to derive each length (please check):

EF = sqrt( 2^2 + 2^2 ) = 2*sqrt(2)
FG =3,

So, parallelogram's perimeter is 2*EF+2*FG = 4*sqrt(2)+6=11.66

Triangle:

AB = sqrt( 2^2 + 3^2) = sqrt(13)
BC= sqrt(1^2_5^2)=sqrt(26)
AC=sqrt(2^2+3^2) = sqrt(13)

Total = 12.31

Difference Triangle - Parallelogram = 12.31-11.66 = 0.65

What about the LAST one? :P