Answer:
a. Isosceles
b. It has two equal angles
Step-by-step explanation:
✅<DCA = <BAC = 50° (alternate interior angles are congruent)
<ACB = 180 - (<BAC + <ABC) (sum of triangle)
<ACB = 180° - (50° + 80°) (substitution)
<ACB = 50°
✅∆ABC is an isosceles triangle judging from the measure of its three angles. ∆ABC has two equal angles. ∆ABC is therefore an isosceles ∆.