(i) Here it is given that in ABCD is a square and ΔEDC is an equilateral triangle.

Hence, we say that AB = BC = CD = DA and ED = EC = DC

Now in ∆ADE and ∆BCE, we have,
AD = BC … given

DE = EC​ … given
∠ADE = ∠BCE … as both angles are sum of 60° and 90°

∴ ∆ADE ≅ ∆BCE

Now by cpct,

AE = BE …(1)

(ii) Here ∠ADE = 90°+ 60° = 150°​

DA = DC … given
DC = DE … given

∴ DA = DE

This means that sides of square and triangles are equal.

∴ ∆ADE and ∆BCE are isosceles triangles.

Hence, ∠DAE = ∠DEA = (180° − 150°) = 30°/2 =15°