Răspuns:
MP//AD=>
MP//BC=>
MP//CN (1
MN//AB=>
MN//CD=>
MN//CP (2
Din (1 si (2=>
PCNM paralelogram( conf teoremei ca laturile opuse sun paralele 2 cate 2)
b) AD//MP
AM si DP concurente=>
patrulaterul AMPD trapez
Deoarece MP//AD=>conf TFA ΔCMP~ΔCAD=>
CM/CA=MP/AD=CP/CD
CM/CA=MP/AD
10/15=MP/6
MP=6*10/15=60/15=4cm
CM/CA=CP/CD
10/15=CP/12
CP=10*12/15=120/15=8cm=>
DP=12-8=4cm
Perimetru=AD+DP+PM+AM=
AM=AC-AM=15-10=5cm
6+4+4+5=19cm
Explicație pas cu pas:
