What is the answer

Dear Student,
Solution) Let measure of an angle be x degree.
Its supplement = (180 - x)⁰
Therefore, acc. to question,
x  = 3(180 ​​​​​​- x)⁰ - 80⁰
$$\begin{gathered} \Rightarrow \mathrm{x}={540}^0-3\mathrm{x}-{80}^0 \\ \Rightarrow \mathrm{x}+3\mathrm{x}={460}^0 \\ \Rightarrow 4\mathrm{x}={460}^0 \\ \Rightarrow \mathrm{x}=\frac{{460}^0}{4}={115}^0 \\ \mathrm{Hence}, \mathrm{the} \mathrm{angle} \mathrm{measured} \mathrm{is} {115}^0. \\ \mathrm{Regards}! \end{gathered}$$