In the figure, ABCD is a quadrilateral in which \(\angle ADC=105^\circ ~and~ \angle ADC=~\angle ABC. Find \angle CBE\).
Given ∠ADC = 105∘ and ∠ADC= ∠ABC
∴ ∠ABC =105∘
∠ABC+∠CBE=180∘ (∵exterior angle+interior angle=180∘)
∠CBE=180∘−105∘=75∘
Hence, ∠CBE=75∘.