Question

1. Fie DEF un triunghi care are aria egala cu 5 radical din 3 cm patrati. Daca DE=4 cm si DF= 5 cm, aflati tg D.

Answer 1

A=$\frac{DE.DF.sin(D)}{2} =5 \sqrt{3} \\ =10 \sqrt{3}$
$sin(D)= \frac{ \sqrt{3} }{2}$
m(D)=60
tg(D)=$\sqrt{3}$