The measure of the angle which is equal to its complement is_______.

$$\begin{gathered} \mathrm{Let} \mathrm{an} \mathrm{angle} \mathrm{be} \mathrm{x}° \mathrm{which} \mathrm{is} \mathrm{it}\text{'}\mathrm{s} \mathrm{own} \mathrm{compliment}. \\ \mathrm{We} \mathrm{know} \mathrm{that} \mathrm{the} \mathrm{sum} \mathrm{of} \mathrm{two} \mathrm{complement} \mathrm{angles} \mathrm{are} \mathrm{equal} \mathrm{to} 90° \\ \mathrm{Therefore}, \\ \mathrm{x}°+\mathrm{x}°=90° \\ \Rightarrow 2\mathrm{x}°=90° \\ \Rightarrow \mathrm{x}°=45° \end{gathered}$$