In the accompanying diagram , ABCD is a parallelogram EC DC , B = E and m please help

∠CDE = 10°

Step-by-step explanation:

In parallelogram,adjacent angles are supplementary.

∠A + ∠B = 180

100 + ∠B = 180

         ∠B =180 - 100

         ∠B = 80

∠E ≅ ∠B

∠E = 80

EC ⊥ DC

∠DCE = 90°

In ΔDCE,

∠DCE + ∠CED + ∠CDE = 180    {Angle sum property of triangle}

90 + 80 + ∠CDE = 180

        170 + ∠CDE = 180

                 ∠CDE = 180 - 170

∠CDE = 10°