Diagonals of a square are perpendicular bisectors of each other.
seg JL = seg IK
∠IMJ=90∘
∠JIL=90∘[Angle of a square]
Diagonals of a square bisect opposite angles.
∠JIK=902=45∘
∠IJK=90∘ [Angle of a square]
∠LJK=902=45∘
Hence measures of ∠IMJ,∠JIK,∠LJK are 90∘,45∘ and 45∘.