Question

calculate the value of x in each of the following figures​

Answer 1

Consider the ΔABC

∠ACD is an exterior angle.

So,

   ∠ACD = ∠CAB + ∠ABC

   ∠ACD = 30° + 40°

   ∠ACD = 70°

Now consider ΔECD

∠DEA is an exterior angle.

So,

   ∠DEA = ∠ACD + ∠CDE

   ∠DEA = 70° + 50°

   ∠DEA = 120°

i.e., x° = 120°

HOPE IT HELPS!!