Answer:
The angle of AEF is 90°.
Explanation:
Given that DEF is an equilateral triangle so all angles are the same which is 60° and in a regular square, all angles are 90°. Next, we have to find ∠ADE :
∠EDF = 60° / ∠CDF = 180° / ∠CDA = 90°
∠ADE = 180° - ∠EDF∠CDA
∠ADE = 180° - 60° - 90°
∠ADE = 30°
Given that ADE is an isosceles triangle so ∠ADE and ∠AED have the same angles. Lastly, we have to find ∠AEF by adding ∠AED and ∠DEF together :
∠AED = 30° / ∠DEF = 60°
∠AEF = ∠AED + ∠DEF
∠AEF = 30° + 60°
∠AEF = 90°