[tex]\large \mathfrak{Solution : }[/tex]
From the above statement we can assume an angle and its complement as x and (90° - x)
now, it's goven that the angle and it's complement are equal, so
i hope it helped...
Let the angle be x
ATQ
[tex]\\ \sf\longmapsto x=90-x[/tex]
[tex]\\ \sf\longmapsto x+x=90[/tex]
[tex]\\ \sf\longmapsto 2x=90[/tex]
[tex]\\ \sf\longmapsto x=\dfrac{90}{2}[/tex]
[tex]\\ \sf\longmapsto x=45[/tex]