1 ) ABC 2) DE || BC
1 ) You have to show that angle ACB and angle ABC is equal.
2 ) You have to state that DE || BC.
Well we know that ∠ACB≅∠ABC because ΔABC is isosceles, so base angles theorem applies.
So m∠DCE=m∠DEC=35° because of base angles theorem, and because m∠DCE=m∠ACB-m∠ECB=70°-35°
Finally, DE║CB because the alternate interior angles ∠ECB≅∠DEC
i dont get
given: ac = ab, cd = de
m∠abc = 70°, m∠ ecb = 35°