Question

Un triunghi isoscel ABC are AB=AC=30 cm si BC=36cm. Calculati:
-aria triunghiului
-tg unghiului B
-sin unghiului A

Answer 1

a)Ducem,perpendiculara,din,A,pe,BC,si,notam,cu,M,piciorul,acesteia.Avem,BM=MC=BC/2=36/2=18
Din,tr.dr.AMB,cu,t.Pit.aflam,AM,care,este,inaltime,in,tr.isoscel,ABC
AMpatrat+BMpatrat=ABpatrat
AMpatrat=900-324
AMpatrat=576=>AM=24cm
Aria=bxh/2=36x24/2=>Aria=432cm,patrati

b)tgB=cateta,opusa/cateta,alaturata=24/18=4/3

c)sinBAM=cateta,opusa/ipotenuza=18/30=3/5=sinMAC
=>sinBAC=2x3/5=6/5