U konveksnom četverokutu ABCDABCDABCD vrijedi ∡BAC=48°,∡CAD=66°,∡CBD=∡DBA.\measuredangle BAC = 48°, \quad \measuredangle CAD = 66°, \quad \measuredangle CBD = \measuredangle DBA.∡BAC=48°,∡CAD=66°,∡CBD=∡DBA. Odredi kut ∡BDC\measuredangle BDC∡BDC.