Question

va rog mult ex 5 si 6​

Answer 1

Răspuns:

Explicație pas cu pas:

5. BC=12

Daca m(∡c)=30°⇒ AB=6 si 2AD=AC

Aplicam Pitagora in ΔABC

BC²=AB²+AC²

AC²=144-36=108

AC=6√3⇒ AD=3√3

Aplicam in ΔABC teorema catetei

AB²=BD×BC

36=BD×12

BD=3⇒CD=12-3=9

$A_{ABD}=\frac{AB\cdot BD}{2} =\frac{9\sqrt{3} }{2}$

$A_{ACD}=\frac{AD\cdot CD}{2} =\frac{27\sqrt{3} }{2}$

$\frac{A_{ABD}}{A_{ACD}} =\frac{1}{3}$

6.

4×4+3×4+12×4=16+12+48=76dm