Given, (∠B–∠A)=40° ----(1) (∠C–∠D)=20° ----(2) Adding (1) and (2), we get, ⇒∠B+∠C=60°+∠A+∠D ⇒∠A+∠D=∠B+∠C–60° ----(3) Now, Sum of all angles of a trapezium = 360° ⇒ ∠A + ∠B + ∠C + ∠D = 360° Substituting from (3), ⇒2(∠B+∠C)=360°+60° ∴(∠B+∠C)=420°/2=210°