The figure is not drawn to scale. PQ and MN are straight lines. Find ∠a .

∠a = °.

∠MOQ = ∠MOR + ∠ROQ = 90° + 48° = 138°.

PQ and MN are straight lines. So ∠PON and ∠MOQ are vertically opposite angles.

∠a = ∠MOQ = 138°.