Răspuns:
1.
AB=rad[(-2-3)^2 + (-4-2)^2]
AB=rad61
2.
AB=rad[(-2-4)^2 + (2+6)^2]
AB=rad100 =>AB=10
xM=(xA+xB)/2=(4-2)/2=1
yM=(yA+yB)/2=(2-6)/2=(-2)
3.
AB=rad[(9-12)^2 + (12-16)^2]
AB=rad25 =>AB=5
BC=rad[(8-9)^2 + (13-12)^2]
BC=rad2
AC=rad[(8-12)^2 + (13-16)^2]
AC=rad25 =>AC=5 triunghi isoscel
P=5+5+rad2=10+rad2
4.
MN=rad[(-6-0)^2 + (0-8)^2]
MN=rad100 =>MN=10
NP=rad[(0+6)^2 + (-3-0)^2]
NP=rad45 =>NP=3rad5
PQ=rad[(4-0)^2 + (0+3)^2]
PQ=rad25 =>PQ=5
MQ=rad[(4-0)^2 + (0-8)^2]
MQ=rad80 =>MQ=4rad5
P=10+5+3rad5+4rad5=15+7rad5
5.
AB=rad[(16-0)^2 + (0-12)^2]
AB=rad400 =>AB=20
BC=rad[(0-16)^2 + (-12-0)^2]
BC=rad400 =>BC=20
CD=rad[(-9-0)^2 + (0+12)^2]
CD=rad225 =>CD=15
AD=rad[(-9-0)^2 + (0-12)^2]
AD=rad225 =>AD=15
Restul pe foaie.
6.
MN=rad[(-9-0)^2 + (0-12)^2]
MN=rad225 =>MN=15
NP=rad[(16+9)^2 + (0-0)^2]
NP=rad625 =>NP=25
MP=rad[(16-0)^2 + (0-12)^2]
MP=rad400 =>MP=20
Triunghiul este dreptunghic pentru că 15, 20 și 25 sunt numere pitagorice, adică :
15^2 + 20^2 = 25^2
