Problem: In the adjoining figure, ABCD is a square, ABE is an equilateral triangle and point E is outside square ABCD. What is the measure of ∠AED in degrees?
Answer Choices:
A. 10
B. 12.5
C. 15
D. 20
E. 25
Solution:
Since ∠DAE=90∘+60∘=150∘ and DA=AB=AE,∠AED=(2180−150​)∘=15∘.