find the missing angles

[tex]\huge\bold{Given :}[/tex]
Angle a = 39°
Angle c = 123°
[tex]\huge\bold{To\:find :}[/tex]
The measure of angle b.
[tex]\large\mathfrak{{\pmb{\underline{\orange{Solution}}{\orange{:}}}}}[/tex]
∠ b = 18°
[tex]\large\mathfrak{{\pmb{\underline{\red{Step-by-step\:explanation}}{\orange{:}}}}}[/tex]
We know that,
[tex]\sf\pink{Sum\:of\:angles\:of\:a\:triangle\:=\:180°}[/tex]
➪ ∠ a + ∠ b + ∠ c = 180°
➪ 39° + ∠ b + 123° = 180°
➪ ∠ b + 162° = 180°
➪ ∠ b = 180° - 162°
➪ ∠ b = 18°
Therefore, the measure of ∠ b is 18°.
[tex]\large\mathfrak{{\pmb{\underline{\blue{To\:verify}}{\blue{:}}}}}[/tex]
∠ a + ∠ b + ∠ c = 180°
✒ 39° + 18° + 123° = 180°
✒ 180° = 180°
✒ L. H. S. = R. H. S.
[tex]\boxed{Hence\:verified.}[/tex]
[tex]\huge{\textbf{\textsf{{\orange{My}}{\blue{st}}{\pink{iq}}{\purple{ue}}{\red{35}}{\green{♡}}}}}[/tex]