As Li Li commented on your closely related Question, the Law of Cosines gives us a system of three quadratic equations This answer is free for unknowns $x_1,x_2,x_3$:
$$ \begin{align*} x_1^2 + x_2^2 - d_3^2 &= 2x_1 x_2 \cos \theta_3 \\ x_1^2 + x_3^2 - d_2^2 &= 2x_1 x_3 \cos \theta_2 \\ x_2^2 + x_3^2 - d_1^2 &= 2x_2 x_3 \cos \theta_1 \end{align*} $$anyone to edit.
As Li Li commented on your closely related Question, the Law of Cosines gives us a system of three quadratic equations for unknowns $x_1,x_2,x_3$:
$$ \begin{align*} x_1^2 + x_2^2 - d_3^2 &= 2x_1 x_2 \cos \theta_3 \\ x_1^2 + x_3^2 - d_2^2 &= 2x_1 x_3 \cos \theta_2 \\ x_2^2 + x_3^2 - d_1^2 &= 2x_2 x_3 \cos \theta_1 \end{align*} $$
This answer is free for anyone to edit.
As Li Li commented on your closely related Question, the Law of CosinesLaw of Cosines gives us a system of three quadratic equations for unknowns $x_1,x_2,x_3$:
$$ \begin{align*} x_1^2 + x_2^2 - d_3^2 &= 2x_1 x_2 \cos \theta_3 \\ x_1^2 + x_3^2 - d_2^2 &= 2x_1 x_3 \cos \theta_2 \\ x_2^2 + x_3^2 - d_1^2 &= 2x_2 x_3 \cos \theta_1 \end{align*} $$
As Li Li commented on your closely related Question, the Law of Cosines gives us a system of three quadratic equations for unknowns $x_1,x_2,x_3$:
$$ \begin{align*} x_1^2 + x_2^2 - d_3^2 &= 2x_1 x_2 \cos \theta_3 \\ x_1^2 + x_3^2 - d_2^2 &= 2x_1 x_3 \cos \theta_2 \\ x_2^2 + x_3^2 - d_1^2 &= 2x_2 x_3 \cos \theta_1 \end{align*} $$
As Li Li commented on your closely related Question, the Law of Cosines gives us a system of three quadratic equations for unknowns $x_1,x_2,x_3$:
$$ \begin{align*} x_1^2 + x_2^2 - d_3^2 &= 2x_1 x_2 \cos \theta_3 \\ x_1^2 + x_3^2 - d_2^2 &= 2x_1 x_3 \cos \theta_2 \\ x_2^2 + x_3^2 - d_1^2 &= 2x_2 x_3 \cos \theta_1 \end{align*} $$
As Li Li commented on your closely related Question, the Law of Cosines gives us a system of three quadratic equations for unknowns $x_1,x_2,x_3$:
$$ \begin{align*} x_1^2 + x_2^2 - d_3^2 &= 2x_1 x_2 \cos \theta_3 \\ x_1^2 + x_3^2 - d_2^2 &= 2x_1 x_3 \cos \theta_2 \\ x_2^2 + x_3^2 - d_1^2 &= 2x_2 x_3 \cos \theta_1 \end{align*} $$
As Li Li commented on your closely related Question, the Law of Cosines gives us a system of three quadratic equations for unknowns $x_1,x_2,x_3$:
$$ \begin{align*} x_1^2 + x_2^2 - d_3^2 &= 2x_1 x_2 \cos \theta_3 \\ x_1^2 + x_3^2 - d_2^2 &= 2x_1 x_3 \cos \theta_2 \\ x_2^2 + x_3^2 - d_1^2 &= 2x_2 x_3 \cos \theta_1 \end{align*} $$
