Question

Calc . aria unui triunghi dreptunghic ABC in care : 
m(<A)=90 grade
m(<B)= 45 grade
BC = 26 cm 

Answer 1

m(<A)=90 grade
m(<B)= 45 grade⇒m(<C)= 45 grade⇒triunghiul ABC este dreptunghic isoscel
Conform teoremei lui Pitagora  AB²+AC²=BC² UNDE AB=AC⇒AB²=BC²:2=26²:2=338⇒AB=√338⇒AC=√338

a=AB*AC/2=√338*√338/2=338/2=169

Answer 2

=> m(< C)=45 grade , deci catetele AB si AC sunt congruente (AB=AC=x)
stiim ca BC^2=AB^2+AC^2 adica 26^2=2*x^2 de unde x=26 radical 2 cm ;
=> A (ABC) = 26 rad.2*26rad.2 : 2 = 26^2 cm^2=676 cm^2