Răspunsuri

  • Utilizator Brainly
2014-02-23T12:11:25+02:00
Ducem din C perpendiculara CE pe AB; CE II AD, AE=CD=24 ⇒ BE=36-24=12 cm.
cosB =cos 60=1/2=BE/BC ⇒ BC=2BE=24 cm.
CE²=BC²-BE²=576-144=432 ⇒ CE=AD=12√3 cm.
P(ABCD)=36+24+24+12√3=84+12√3 cm.
AC²=AD²+CD²=432+576=1008 ⇒ AC=√1008=12√7 cm.
BD²=AB²+AD²=1296+432=1728 ⇒ BD=√1728=24√3 cm.

11 4 11
2014-02-23T12:14:20+02:00
Notam cu O perpendiculara din C pe baza AB
in triunghiul dreptunghic COB, O=90 grade avem
tg 60=CO/OB
OB=36-24=12 cm
=> v3=CO/12 => CO=12v3 cm =AD(v3-radical din 3 2...)
in triunghiul dreptunghic COB, O=90 grade avem
cos 60=OB/BC => 1/2=12/BC
BC=2*12=24 cm
P=36+24+24+12v3=84+12v3=12(7+v3)cm
 in triunghiul dreptunghic ADC, D= 90 aplicam teoremalui Pitagora si avem
AC2=AD2+DC2=432+576=1008
AC=12v7 cm
in triunghiul dreptunghic DAB, A=90 aplicam teoremalui Pitagora si avem
BD2=AD2+AB2=432+1296=1728
BD= v1728=12v11 cm
6 4 6