Question

Va rog frumos !!!!!!!!!

Answer 1

a)conform th.PIT.inΔABD⇒AD²=AB²-BD²=9²-3²=81-9=72⇒AD=√72=6√2cm
conform th.inaltimii:AD²=BD×DC⇒DC=AD²/BD=72/3=24cm
BC=CD+DB=24+3=27cm
b)inΔABC  aplic th.pit.⇒AB²=BC²-AC²=256-64=192⇒AB=√192⇒AB=8√3cm
AB×AC=AD×BC⇒AD=AB×AC/BC=8×8√3/16⇒AD=4√3cm
inΔCDA aplic th.pit.:CD²=AC²-AD²=64-48=16⇒CD=√16=4cm
c)BC=BD+CD⇒CD=BC-BD=84-21⇒CD=63cm
conform th.inaltimii⇒AD²=CD×DB=63×21=1323⇒AD=√1323=21√3cm
inΔADB aplic th.pit⇒AB²=AD²+DB²=1323+441=1764⇒AB=√1764=42 cm
inΔADC aplic th.pit.⇒AC²=AD²+CD²=1323+3969=5292⇒AC=√5292=42√3cm