Browse · harp Print → smc geometry intermediate 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? (A) 10 (B) 12.5 (C) 15 (D) 20 Solution — click to reveal Notice that ∡DAE=90∘+60∘=150∘ and that AD=AE. Then triangle ADE is isosceles, so ∡AED=2180∘−150∘=15. Final answer C ← Previous problem Next problem →