Question

HELPPPP PLS
4) a)
5) a)
6) a)
7) a)

Answer 1

Exercitiul 4:
a)
A▲=(DE×DF×sin(D))/2
16√15=6√3×6√5×sin(D)/2=> 32√15=36√15×sin(D)=>
sin(D)=32√15/36√15=32/36=8/9

Exercitiul 5:
a)
A=(AB×AC×sin(A))/2=>
12√6=(16×3√6×sin(A))/2=>
24√6=48√6×sin(A)=>sin(A)=24√6/48√6=1/2
sin30°=1/2=>m(A)=30°

Exercitiul 6:
a)
A▲ech=(l×l√3)/4
A▲ech=(4×4√3)/4=4√3 (cm^2)

Exercitiul 7:
a)
A▲ech=4√3=(l×l√3)/4=>l×l√3=16√3=>l=4 (cm)
P=3l=3×4=12 (cm)