Question

a) What type of triangle is triangle ABC? b) Give reasons for your answer. I need the correct answer for B with Reasons Not "ab and ac are the same" any word other than the same ​

Answer 1

Δ ABC is isosceles

Explanation:

∠ ABC and ∠ BCE are alternate angles and are congruent , that is

∠ BCE = ∠ ABC = 80°

since DE id a straight line then the angles lying on it sum to 180° , that is

∠ ACD + ∠ ACB + ∠ BCE = 180°

50° + ∠ ACB + 80° = 180°

∠ ACB + 130° = 180° ( subtract 130° from both sides )

∠ ACB = 50°

∠ BAC and ∠ ACD are alternate angles and are congruent , that is

∠ BAC = 50°

then

∠ BAC = ∠ ACB = 50°

Since the 2 base angles are congruent then Δ ABC is isosceles