FC = FE (manufacturing)
∴∠ FEC =∠ FCE = 24 (equilateral and angular)
∠∠ Dirk +∠ EDC+∠ DCE = 180 (triangle interior angle and 180)
∠∠EDC =∠DCE = 24 (known)
∴∠DEC= 132
∴∠DEF=∠DEC-∠FEC= 108
∠∠ADE =∠ADC-∠EDC = 96-24 = 72
∠∠DEF =∠DAE+∠ADE (the nature of triangle outer angle)
∴∠DAE=36
∠∠EAB =∠ Bad -∠DAE=96 -36 =60
∠∠ade+∠DEA+∠DAE = 180 (triangle interior angle sum 180)
∴∠DEA=∠ADE=72
∴AD=AE (equilateral)
AD = AB (known)
∴AB=AE (equivalent substitution)
∴△ABE is an equilateral triangle (an isosceles triangle with an internal angle of 60 is an equilateral triangle).