Can we have two obtuse angles whose sum is
(a) a reflex angle? (b) a complete angle?
(a) Yes; e.g., \(100^{\circ}+110^{\circ}=210^{\circ}\) (reflex).
(b) No; each obtuse angle is \(>90^{\circ}\) and \(<180^{\circ}\), so their sum is \(>180^{\circ}\) but \(<360^{\circ}\); it can never be \(360^{\circ}\).
By range considerations for obtuse angles.